Case Reports

Cosmetic procedures carry inherent risks of adverse events. Transient and permanent alopecia are rare complications of these procedures. Although they have not been fully elucidated, several pathologic mechanisms for hair loss following cosmetic procedures have been proposed, including extravascular compression (a phenomenon that has been well documented in bed­ridden patients) as well as intravascular occlusion leading to inflammation and necrosis, which has been associated with hyaluronic acid (HA) fillers.¹ Cases of alopecia also have been reported following mesotherapy and calcium hydroxyapatite, deoxycholic acid, and botulinum toxin injections.² We report a case of alopecia resulting from poly-L-lactic acid (PLLA) injection in a 35-year-old woman with the intent to raise awareness of this rare adverse event.

Case Report

A healthy 35-year-old woman received aesthetic PLLA injections on the face and frontal hairline performed by an outside dermatologist using the vector technique. During the procedure, the patient experienced intense itchiness at the right temporal artery vascular territory and reported a substantial headache the next day. She also presented with erythema and edema of the frontal and right parietal scalp with a well-delimited livedoid vascular area along the temporal artery territory on the right side of the head 1 day after the procedure (Figure 1). These signs were reported to the outside dermatologist who performed the procedure, but they were not assumed to be adverse events at that time.

The condition persisted for 4 days followed by the development of an irregular 3×2-cm patch of alopecia on the right parietal scalp. A 3-day course of self-administered oral prednisolone 0.2 mg/kg/d was prescribed.

Twenty-seven days after the procedure, the patient presented to our trichology clinic for evaluation of a single patch of nonscarring alopecia on the right parietal scalp. Trichoscopy showed multiple yellow and black dots, broken hairs, pigment deposits, and an erythematous background mainly composed of linear telangiectatic vessels (Figure 2). Histopathologic analysis revealed a lymphocytic inflammatory infiltrate surrounding the follicular units that was compatible with an alopecia areata–like pattern as well as PLLA deposits in the subcutaneous tissue forming foreign body granulomas (Figure 3). The diagnosis of PLLA-induced alopecia was made based on the detection of PLLA at the biopsy site within the patchy alopecia.

Comment

Poly-L-lactic acid is a biostimulator synthesized from the α-hydroxy acid family in 1954 that has been safely used in suture materials, resorbable plates, and orthopedic screws.⁴ Alopecia has been reported as a systemic allergic reaction to biodegradable screws following an orthopedic procedure.⁵ Prior reports of embolization and retinal ischemia with PLLA have raised concerns regarding its occlusive potential.^6-9

Approved by the US Food and Drug Administration in 2004 for soft tissue restoration in HIV-related lipoatrophy, PLLA was expanded to cosmetic applications in 2009. As previously reported with HA fillers, we hypothesize that extravascular compression resulting from the placement of the filler material (due to the volume injected in the scalp area) contributes to the development of alopecia plus PLLA embolism–induced ischemic alopecia in the affected areas.¹⁰ In our case, the diagnosis of PLLA-induced alopecia was confirmed based on the finding of the filler material in the subcutaneous tissue on histopathology, probably due to embolization. Moreover, trichoscopic findings were all similar to those described after HA embolization.¹¹ The features found in our patient due to the PLLA local reaction were similar to those seen in other conditions such as alopecia areata, pressure alopecia, and chemotherapy-induced alopecia; therefore, histopathology confirmation is mandatory in cases of hair loss associated with PLLA.

The emergence of a secondary patch of alopecia prompts consideration of an intrinsic late inflammatory propensity of PLLA. Immune cells recognize PLLA as a foreign body, and subclinical inflammatory foreign body reactions can cause PLLA-induced collagen synthesis.¹² This phenomenon underscores the need for further investigation into the immunologic implications of PLLA in alopecia pathogenesis.

The angiogenic properties of the anagen phase require an adequate blood supply for effective hair growth; therefore, the lack of blood and nutrient supply to the hair bulb triggers miniaturization, a possible explanation for the hair thinning found in the alopecic patch.¹³

Conclusion

Alopecia as an adverse effect of cosmetic procedures can be distressing for patients, even when reversible. A detailed understanding of scalp anatomy is critical for satisfactory outcomes with aesthetic procedures. Physicians must pay attention to the amount and area of material injected in order to avoid possible mechanisms of ischemia—embolization and/or extravascular compression—especially in highly vascularized areas.

We present a rare report of alopecia as an adverse event of PLLA injection. Dermatologists must be aware of this rare condition, and trichoscopy combined with histopathologic analysis are encouraged for early recognition and proper management.

Cosmetic procedures carry inherent risks of adverse events. Transient and permanent alopecia are rare complications of these procedures. Although they have not been fully elucidated, several pathologic mechanisms for hair loss following cosmetic procedures have been proposed, including extravascular compression (a phenomenon that has been well documented in bed­ridden patients) as well as intravascular occlusion leading to inflammation and necrosis, which has been associated with hyaluronic acid (HA) fillers.¹ Cases of alopecia also have been reported following mesotherapy and calcium hydroxyapatite, deoxycholic acid, and botulinum toxin injections.² We report a case of alopecia resulting from poly-L-lactic acid (PLLA) injection in a 35-year-old woman with the intent to raise awareness of this rare adverse event.

Case Report

A healthy 35-year-old woman received aesthetic PLLA injections on the face and frontal hairline performed by an outside dermatologist using the vector technique. During the procedure, the patient experienced intense itchiness at the right temporal artery vascular territory and reported a substantial headache the next day. She also presented with erythema and edema of the frontal and right parietal scalp with a well-delimited livedoid vascular area along the temporal artery territory on the right side of the head 1 day after the procedure (Figure 1). These signs were reported to the outside dermatologist who performed the procedure, but they were not assumed to be adverse events at that time.

The condition persisted for 4 days followed by the development of an irregular 3×2-cm patch of alopecia on the right parietal scalp. A 3-day course of self-administered oral prednisolone 0.2 mg/kg/d was prescribed.

Twenty-seven days after the procedure, the patient presented to our trichology clinic for evaluation of a single patch of nonscarring alopecia on the right parietal scalp. Trichoscopy showed multiple yellow and black dots, broken hairs, pigment deposits, and an erythematous background mainly composed of linear telangiectatic vessels (Figure 2). Histopathologic analysis revealed a lymphocytic inflammatory infiltrate surrounding the follicular units that was compatible with an alopecia areata–like pattern as well as PLLA deposits in the subcutaneous tissue forming foreign body granulomas (Figure 3). The diagnosis of PLLA-induced alopecia was made based on the detection of PLLA at the biopsy site within the patchy alopecia.

Comment

Poly-L-lactic acid is a biostimulator synthesized from the α-hydroxy acid family in 1954 that has been safely used in suture materials, resorbable plates, and orthopedic screws.⁴ Alopecia has been reported as a systemic allergic reaction to biodegradable screws following an orthopedic procedure.⁵ Prior reports of embolization and retinal ischemia with PLLA have raised concerns regarding its occlusive potential.^6-9

Approved by the US Food and Drug Administration in 2004 for soft tissue restoration in HIV-related lipoatrophy, PLLA was expanded to cosmetic applications in 2009. As previously reported with HA fillers, we hypothesize that extravascular compression resulting from the placement of the filler material (due to the volume injected in the scalp area) contributes to the development of alopecia plus PLLA embolism–induced ischemic alopecia in the affected areas.¹⁰ In our case, the diagnosis of PLLA-induced alopecia was confirmed based on the finding of the filler material in the subcutaneous tissue on histopathology, probably due to embolization. Moreover, trichoscopic findings were all similar to those described after HA embolization.¹¹ The features found in our patient due to the PLLA local reaction were similar to those seen in other conditions such as alopecia areata, pressure alopecia, and chemotherapy-induced alopecia; therefore, histopathology confirmation is mandatory in cases of hair loss associated with PLLA.

The emergence of a secondary patch of alopecia prompts consideration of an intrinsic late inflammatory propensity of PLLA. Immune cells recognize PLLA as a foreign body, and subclinical inflammatory foreign body reactions can cause PLLA-induced collagen synthesis.¹² This phenomenon underscores the need for further investigation into the immunologic implications of PLLA in alopecia pathogenesis.

The angiogenic properties of the anagen phase require an adequate blood supply for effective hair growth; therefore, the lack of blood and nutrient supply to the hair bulb triggers miniaturization, a possible explanation for the hair thinning found in the alopecic patch.¹³

Conclusion

Alopecia as an adverse effect of cosmetic procedures can be distressing for patients, even when reversible. A detailed understanding of scalp anatomy is critical for satisfactory outcomes with aesthetic procedures. Physicians must pay attention to the amount and area of material injected in order to avoid possible mechanisms of ischemia—embolization and/or extravascular compression—especially in highly vascularized areas.

We present a rare report of alopecia as an adverse event of PLLA injection. Dermatologists must be aware of this rare condition, and trichoscopy combined with histopathologic analysis are encouraged for early recognition and proper management.

Cosmetic procedures carry inherent risks of adverse events. Transient and permanent alopecia are rare complications of these procedures. Although they have not been fully elucidated, several pathologic mechanisms for hair loss following cosmetic procedures have been proposed, including extravascular compression (a phenomenon that has been well documented in bed­ridden patients) as well as intravascular occlusion leading to inflammation and necrosis, which has been associated with hyaluronic acid (HA) fillers.¹ Cases of alopecia also have been reported following mesotherapy and calcium hydroxyapatite, deoxycholic acid, and botulinum toxin injections.² We report a case of alopecia resulting from poly-L-lactic acid (PLLA) injection in a 35-year-old woman with the intent to raise awareness of this rare adverse event.

Case Report

A healthy 35-year-old woman received aesthetic PLLA injections on the face and frontal hairline performed by an outside dermatologist using the vector technique. During the procedure, the patient experienced intense itchiness at the right temporal artery vascular territory and reported a substantial headache the next day. She also presented with erythema and edema of the frontal and right parietal scalp with a well-delimited livedoid vascular area along the temporal artery territory on the right side of the head 1 day after the procedure (Figure 1). These signs were reported to the outside dermatologist who performed the procedure, but they were not assumed to be adverse events at that time.

The condition persisted for 4 days followed by the development of an irregular 3×2-cm patch of alopecia on the right parietal scalp. A 3-day course of self-administered oral prednisolone 0.2 mg/kg/d was prescribed.

Twenty-seven days after the procedure, the patient presented to our trichology clinic for evaluation of a single patch of nonscarring alopecia on the right parietal scalp. Trichoscopy showed multiple yellow and black dots, broken hairs, pigment deposits, and an erythematous background mainly composed of linear telangiectatic vessels (Figure 2). Histopathologic analysis revealed a lymphocytic inflammatory infiltrate surrounding the follicular units that was compatible with an alopecia areata–like pattern as well as PLLA deposits in the subcutaneous tissue forming foreign body granulomas (Figure 3). The diagnosis of PLLA-induced alopecia was made based on the detection of PLLA at the biopsy site within the patchy alopecia.

Comment

Poly-L-lactic acid is a biostimulator synthesized from the α-hydroxy acid family in 1954 that has been safely used in suture materials, resorbable plates, and orthopedic screws.⁴ Alopecia has been reported as a systemic allergic reaction to biodegradable screws following an orthopedic procedure.⁵ Prior reports of embolization and retinal ischemia with PLLA have raised concerns regarding its occlusive potential.^6-9

Approved by the US Food and Drug Administration in 2004 for soft tissue restoration in HIV-related lipoatrophy, PLLA was expanded to cosmetic applications in 2009. As previously reported with HA fillers, we hypothesize that extravascular compression resulting from the placement of the filler material (due to the volume injected in the scalp area) contributes to the development of alopecia plus PLLA embolism–induced ischemic alopecia in the affected areas.¹⁰ In our case, the diagnosis of PLLA-induced alopecia was confirmed based on the finding of the filler material in the subcutaneous tissue on histopathology, probably due to embolization. Moreover, trichoscopic findings were all similar to those described after HA embolization.¹¹ The features found in our patient due to the PLLA local reaction were similar to those seen in other conditions such as alopecia areata, pressure alopecia, and chemotherapy-induced alopecia; therefore, histopathology confirmation is mandatory in cases of hair loss associated with PLLA.

The emergence of a secondary patch of alopecia prompts consideration of an intrinsic late inflammatory propensity of PLLA. Immune cells recognize PLLA as a foreign body, and subclinical inflammatory foreign body reactions can cause PLLA-induced collagen synthesis.¹² This phenomenon underscores the need for further investigation into the immunologic implications of PLLA in alopecia pathogenesis.

The angiogenic properties of the anagen phase require an adequate blood supply for effective hair growth; therefore, the lack of blood and nutrient supply to the hair bulb triggers miniaturization, a possible explanation for the hair thinning found in the alopecic patch.¹³

Conclusion

Alopecia as an adverse effect of cosmetic procedures can be distressing for patients, even when reversible. A detailed understanding of scalp anatomy is critical for satisfactory outcomes with aesthetic procedures. Physicians must pay attention to the amount and area of material injected in order to avoid possible mechanisms of ischemia—embolization and/or extravascular compression—especially in highly vascularized areas.

We present a rare report of alopecia as an adverse event of PLLA injection. Dermatologists must be aware of this rare condition, and trichoscopy combined with histopathologic analysis are encouraged for early recognition and proper management.

What is the world’s most dangerous tree? According to Guinness World Records¹ (and one unlucky contestant on the wilderness survival reality show Naked and Afraid,² who got its sap in his eyes and needed to be evacuated for treatment), the manchineel tree (Hippomane mancinella) has earned this designation.^1-3 Manchineel trees are part of the strand vegetation of islands in the West Indies and along the Caribbean coasts of South and Central America, where their copious root systems help reduce coastal erosion. In the United States, this poisonous tree grows along the southern edge of Florida’s Everglades National Park; the Florida Keys; and the US Virgin Islands, especially Virgin Islands National Park. Although the manchineel tree appears on several endangered species lists,^4-6 there are places within its distribution where it is locally abundant and thus poses a risk to residents and visitors.

The first European description of manchineel toxicity was by Peter Martyr d’Anghiera, a court historian and geographer of Christopher Columbus’s patroness, Isabella I, Queen of Castile and Léon. In the early 1500s, Peter Martyr wrote that on Columbus’s second New World voyage in 1493, the crew encountered a mysterious tree that burned the skin and eyes of anyone who had contact with it.⁷ Columbus called the tree’s fruit manzanilla de la muerte (“little apple of death”) after several sailors became severely ill from eating the fruit.^8,9 Manchineel lore is rife with tales of agonizing death after eating the applelike fruit, and several contemporaneous accounts describe indigenous Caribbean islanders using manchineel’s toxic sap as an arrow poison.¹⁰

Eating manchineel fruit is known to cause abdominal pain, burning sensations in the oropharynx, and esophageal spasms.¹¹ Several case reports mention that consuming the fruit can create an exaggerated parasympathomimetic syndrome due to suspected anticholinesteraselike compounds.^3,11,12 Ophthalmologic injuries include severe conjunctivitis—sometimes extensive enough to cause superficial punctate epithelial keratitis.⁵ Dermatologic injuries have been described, but reports on its histopathologic features are limited. We present a case of manchineel dermatitis in a patient who subsequently underwent a skin biopsy.

Case Report

A 64-year-old physician (S.A.N.) came across a stand of manchineel trees while camping in the Virgin Islands National Park on St. John in the US Virgin Islands (Figure 1). The patient—who was knowledgeable about tropical ecology and was familiar with the tree—was curious about its purported cutaneous toxicity and applied the viscous white sap of a broken branchlet (Figure 2) to a patch of skin measuring 4 cm in diameter on the medial left calf. He took serial photographs of the site on days 2, 4 (Figure 3), 6, and 10 (Figure 4), showing the onset of erythema and the subsequent development of follicular pustules. On day 6, a 4-mm punch biopsy specimen was taken of the most prominent pustule. Histopathology showed a subcorneal acantholytic blister and epidermal spongiosis overlying a mixed perivascular infiltrate and follicular necrosis, which was consistent with irritant contact dermatitis (Figure 5). On day 8, the region became indurated and tender to pressure; however, there was no warmth, edema, purulent drainage, lymphangitic streaks, or other signs of infection. The region was never itchy; it was uncomfortable only with firm direct pressure. The patient applied hot compresses to the site for 10 minutes 1 to 2 times daily for roughly 2 weeks, and the affected area healed fully (without any additional intervention) in approximately 6 weeks.

Comment

Manchineel is a member of the Euphorbiaceae (also known as the euphorb or spurge) family, a mainly tropical or subtropical plant family that includes many useful as well as many toxic species. Examples of useful plants include cassava (Manihot esculenta) and the rubber tree (Hevea brasiliensis). Many euphorbs have well-described toxicities, and many (eg, castor bean, Ricinus communis) are useful in some circumstances and toxic in others.^6,12-14 Many euphorbs are known to cause skin reactions, usually due to toxins in the milky sap that directly irritate the skin or to latex compounds that can induce IgE-mediated contact dermatitis.^9,14

Manchineel contains a complex mix of toxins, though no specific one has been identified as the main cause of the associated irritant contact dermatitis. Manchineel sap (and sap of many other euphorbs) contains phorbol esters that may cause direct pH-induced cytotoxicity leading to keratinocyte necrosis. Diterpenes may augment this cytotoxic effect via induction of proinflammatory cytokines.¹² Pitts et al⁵ pointed to a mixture of oxygenated diterpene esters as the primary cause of toxicity and suggested that their water solubility explained occurrences of keratoconjunctivitis after contact with rainwater or dew from the manchineel tree.

All parts of the manchineel tree—fruit, leaves, wood, and sap—are poisonous. In a retrospective series of 97 cases of manchineel fruit ingestion, the most common symptoms were oropharyngeal pain (68% [66/97]), abdominal pain (42% [41/97]), and diarrhea (37% [36/97]). The same series identified 1 (1%) case of bradycardia and hypotension.³ Contact with the wood, exposure to sawdust, and inhalation of smoke from burning the wood can irritate the skin, conjunctivae, or nasopharynx. Rainwater or dew dripping from the leaves onto the skin can cause dermatitis and ophthalmitis, even without direct contact with the tree.^4,5

Management—There is no specific treatment for manchineel dermatitis. Because it is an irritant reaction and not a type IV hypersensitivity reaction, topical corticosteroids have minimal benefit. A regimen consisting of a thorough cleansing, wet compresses, and observation, as most symptoms resolve spontaneously within a few days, has been recommended.⁴ Our patient used hot compresses, which he believes helped heal the site, although his symptoms lasted for several weeks.

Given that there is no specific treatment for manchineel dermatitis, the wisest approach is strict avoidance. On many Caribbean islands, visitors are warned about the manchineel tree, advised to avoid direct contact, and reminded to avoid standing beneath it during a rainstorm (Figure 6).

Conclusion

This article begins with a question: “What is the world’s most dangerous tree?” Many sources from the indexed medical literature as well as the popular press and social media state that it is the manchineel. Although all parts of the manchineel tree are highly toxic, human exposures are uncommon, and deaths are more apocryphal than actual.

What is the world’s most dangerous tree? According to Guinness World Records¹ (and one unlucky contestant on the wilderness survival reality show Naked and Afraid,² who got its sap in his eyes and needed to be evacuated for treatment), the manchineel tree (Hippomane mancinella) has earned this designation.^1-3 Manchineel trees are part of the strand vegetation of islands in the West Indies and along the Caribbean coasts of South and Central America, where their copious root systems help reduce coastal erosion. In the United States, this poisonous tree grows along the southern edge of Florida’s Everglades National Park; the Florida Keys; and the US Virgin Islands, especially Virgin Islands National Park. Although the manchineel tree appears on several endangered species lists,^4-6 there are places within its distribution where it is locally abundant and thus poses a risk to residents and visitors.

The first European description of manchineel toxicity was by Peter Martyr d’Anghiera, a court historian and geographer of Christopher Columbus’s patroness, Isabella I, Queen of Castile and Léon. In the early 1500s, Peter Martyr wrote that on Columbus’s second New World voyage in 1493, the crew encountered a mysterious tree that burned the skin and eyes of anyone who had contact with it.⁷ Columbus called the tree’s fruit manzanilla de la muerte (“little apple of death”) after several sailors became severely ill from eating the fruit.^8,9 Manchineel lore is rife with tales of agonizing death after eating the applelike fruit, and several contemporaneous accounts describe indigenous Caribbean islanders using manchineel’s toxic sap as an arrow poison.¹⁰

Eating manchineel fruit is known to cause abdominal pain, burning sensations in the oropharynx, and esophageal spasms.¹¹ Several case reports mention that consuming the fruit can create an exaggerated parasympathomimetic syndrome due to suspected anticholinesteraselike compounds.^3,11,12 Ophthalmologic injuries include severe conjunctivitis—sometimes extensive enough to cause superficial punctate epithelial keratitis.⁵ Dermatologic injuries have been described, but reports on its histopathologic features are limited. We present a case of manchineel dermatitis in a patient who subsequently underwent a skin biopsy.

Case Report

A 64-year-old physician (S.A.N.) came across a stand of manchineel trees while camping in the Virgin Islands National Park on St. John in the US Virgin Islands (Figure 1). The patient—who was knowledgeable about tropical ecology and was familiar with the tree—was curious about its purported cutaneous toxicity and applied the viscous white sap of a broken branchlet (Figure 2) to a patch of skin measuring 4 cm in diameter on the medial left calf. He took serial photographs of the site on days 2, 4 (Figure 3), 6, and 10 (Figure 4), showing the onset of erythema and the subsequent development of follicular pustules. On day 6, a 4-mm punch biopsy specimen was taken of the most prominent pustule. Histopathology showed a subcorneal acantholytic blister and epidermal spongiosis overlying a mixed perivascular infiltrate and follicular necrosis, which was consistent with irritant contact dermatitis (Figure 5). On day 8, the region became indurated and tender to pressure; however, there was no warmth, edema, purulent drainage, lymphangitic streaks, or other signs of infection. The region was never itchy; it was uncomfortable only with firm direct pressure. The patient applied hot compresses to the site for 10 minutes 1 to 2 times daily for roughly 2 weeks, and the affected area healed fully (without any additional intervention) in approximately 6 weeks.

Comment

Manchineel is a member of the Euphorbiaceae (also known as the euphorb or spurge) family, a mainly tropical or subtropical plant family that includes many useful as well as many toxic species. Examples of useful plants include cassava (Manihot esculenta) and the rubber tree (Hevea brasiliensis). Many euphorbs have well-described toxicities, and many (eg, castor bean, Ricinus communis) are useful in some circumstances and toxic in others.^6,12-14 Many euphorbs are known to cause skin reactions, usually due to toxins in the milky sap that directly irritate the skin or to latex compounds that can induce IgE-mediated contact dermatitis.^9,14

Manchineel contains a complex mix of toxins, though no specific one has been identified as the main cause of the associated irritant contact dermatitis. Manchineel sap (and sap of many other euphorbs) contains phorbol esters that may cause direct pH-induced cytotoxicity leading to keratinocyte necrosis. Diterpenes may augment this cytotoxic effect via induction of proinflammatory cytokines.¹² Pitts et al⁵ pointed to a mixture of oxygenated diterpene esters as the primary cause of toxicity and suggested that their water solubility explained occurrences of keratoconjunctivitis after contact with rainwater or dew from the manchineel tree.

All parts of the manchineel tree—fruit, leaves, wood, and sap—are poisonous. In a retrospective series of 97 cases of manchineel fruit ingestion, the most common symptoms were oropharyngeal pain (68% [66/97]), abdominal pain (42% [41/97]), and diarrhea (37% [36/97]). The same series identified 1 (1%) case of bradycardia and hypotension.³ Contact with the wood, exposure to sawdust, and inhalation of smoke from burning the wood can irritate the skin, conjunctivae, or nasopharynx. Rainwater or dew dripping from the leaves onto the skin can cause dermatitis and ophthalmitis, even without direct contact with the tree.^4,5

Management—There is no specific treatment for manchineel dermatitis. Because it is an irritant reaction and not a type IV hypersensitivity reaction, topical corticosteroids have minimal benefit. A regimen consisting of a thorough cleansing, wet compresses, and observation, as most symptoms resolve spontaneously within a few days, has been recommended.⁴ Our patient used hot compresses, which he believes helped heal the site, although his symptoms lasted for several weeks.

Given that there is no specific treatment for manchineel dermatitis, the wisest approach is strict avoidance. On many Caribbean islands, visitors are warned about the manchineel tree, advised to avoid direct contact, and reminded to avoid standing beneath it during a rainstorm (Figure 6).

Conclusion

This article begins with a question: “What is the world’s most dangerous tree?” Many sources from the indexed medical literature as well as the popular press and social media state that it is the manchineel. Although all parts of the manchineel tree are highly toxic, human exposures are uncommon, and deaths are more apocryphal than actual.

What is the world’s most dangerous tree? According to Guinness World Records¹ (and one unlucky contestant on the wilderness survival reality show Naked and Afraid,² who got its sap in his eyes and needed to be evacuated for treatment), the manchineel tree (Hippomane mancinella) has earned this designation.^1-3 Manchineel trees are part of the strand vegetation of islands in the West Indies and along the Caribbean coasts of South and Central America, where their copious root systems help reduce coastal erosion. In the United States, this poisonous tree grows along the southern edge of Florida’s Everglades National Park; the Florida Keys; and the US Virgin Islands, especially Virgin Islands National Park. Although the manchineel tree appears on several endangered species lists,^4-6 there are places within its distribution where it is locally abundant and thus poses a risk to residents and visitors.

The first European description of manchineel toxicity was by Peter Martyr d’Anghiera, a court historian and geographer of Christopher Columbus’s patroness, Isabella I, Queen of Castile and Léon. In the early 1500s, Peter Martyr wrote that on Columbus’s second New World voyage in 1493, the crew encountered a mysterious tree that burned the skin and eyes of anyone who had contact with it.⁷ Columbus called the tree’s fruit manzanilla de la muerte (“little apple of death”) after several sailors became severely ill from eating the fruit.^8,9 Manchineel lore is rife with tales of agonizing death after eating the applelike fruit, and several contemporaneous accounts describe indigenous Caribbean islanders using manchineel’s toxic sap as an arrow poison.¹⁰

Eating manchineel fruit is known to cause abdominal pain, burning sensations in the oropharynx, and esophageal spasms.¹¹ Several case reports mention that consuming the fruit can create an exaggerated parasympathomimetic syndrome due to suspected anticholinesteraselike compounds.^3,11,12 Ophthalmologic injuries include severe conjunctivitis—sometimes extensive enough to cause superficial punctate epithelial keratitis.⁵ Dermatologic injuries have been described, but reports on its histopathologic features are limited. We present a case of manchineel dermatitis in a patient who subsequently underwent a skin biopsy.

Case Report

A 64-year-old physician (S.A.N.) came across a stand of manchineel trees while camping in the Virgin Islands National Park on St. John in the US Virgin Islands (Figure 1). The patient—who was knowledgeable about tropical ecology and was familiar with the tree—was curious about its purported cutaneous toxicity and applied the viscous white sap of a broken branchlet (Figure 2) to a patch of skin measuring 4 cm in diameter on the medial left calf. He took serial photographs of the site on days 2, 4 (Figure 3), 6, and 10 (Figure 4), showing the onset of erythema and the subsequent development of follicular pustules. On day 6, a 4-mm punch biopsy specimen was taken of the most prominent pustule. Histopathology showed a subcorneal acantholytic blister and epidermal spongiosis overlying a mixed perivascular infiltrate and follicular necrosis, which was consistent with irritant contact dermatitis (Figure 5). On day 8, the region became indurated and tender to pressure; however, there was no warmth, edema, purulent drainage, lymphangitic streaks, or other signs of infection. The region was never itchy; it was uncomfortable only with firm direct pressure. The patient applied hot compresses to the site for 10 minutes 1 to 2 times daily for roughly 2 weeks, and the affected area healed fully (without any additional intervention) in approximately 6 weeks.

Comment

Manchineel is a member of the Euphorbiaceae (also known as the euphorb or spurge) family, a mainly tropical or subtropical plant family that includes many useful as well as many toxic species. Examples of useful plants include cassava (Manihot esculenta) and the rubber tree (Hevea brasiliensis). Many euphorbs have well-described toxicities, and many (eg, castor bean, Ricinus communis) are useful in some circumstances and toxic in others.^6,12-14 Many euphorbs are known to cause skin reactions, usually due to toxins in the milky sap that directly irritate the skin or to latex compounds that can induce IgE-mediated contact dermatitis.^9,14

Manchineel contains a complex mix of toxins, though no specific one has been identified as the main cause of the associated irritant contact dermatitis. Manchineel sap (and sap of many other euphorbs) contains phorbol esters that may cause direct pH-induced cytotoxicity leading to keratinocyte necrosis. Diterpenes may augment this cytotoxic effect via induction of proinflammatory cytokines.¹² Pitts et al⁵ pointed to a mixture of oxygenated diterpene esters as the primary cause of toxicity and suggested that their water solubility explained occurrences of keratoconjunctivitis after contact with rainwater or dew from the manchineel tree.

All parts of the manchineel tree—fruit, leaves, wood, and sap—are poisonous. In a retrospective series of 97 cases of manchineel fruit ingestion, the most common symptoms were oropharyngeal pain (68% [66/97]), abdominal pain (42% [41/97]), and diarrhea (37% [36/97]). The same series identified 1 (1%) case of bradycardia and hypotension.³ Contact with the wood, exposure to sawdust, and inhalation of smoke from burning the wood can irritate the skin, conjunctivae, or nasopharynx. Rainwater or dew dripping from the leaves onto the skin can cause dermatitis and ophthalmitis, even without direct contact with the tree.^4,5

Management—There is no specific treatment for manchineel dermatitis. Because it is an irritant reaction and not a type IV hypersensitivity reaction, topical corticosteroids have minimal benefit. A regimen consisting of a thorough cleansing, wet compresses, and observation, as most symptoms resolve spontaneously within a few days, has been recommended.⁴ Our patient used hot compresses, which he believes helped heal the site, although his symptoms lasted for several weeks.

Given that there is no specific treatment for manchineel dermatitis, the wisest approach is strict avoidance. On many Caribbean islands, visitors are warned about the manchineel tree, advised to avoid direct contact, and reminded to avoid standing beneath it during a rainstorm (Figure 6).

Conclusion

This article begins with a question: “What is the world’s most dangerous tree?” Many sources from the indexed medical literature as well as the popular press and social media state that it is the manchineel. Although all parts of the manchineel tree are highly toxic, human exposures are uncommon, and deaths are more apocryphal than actual.

A previously healthy 31-year-old female active-duty Navy sailor working as a calibration technician developed a painful, erythematous, pruritic, indurated plaque on her left breast. The sailor was not lactating and had no known family history of malignancy. Initially, she was treated by her primary care practitioner for presumed mastitis with oral cephalexin and then with oral clindamycin with no symptom improvement. About 2 weeks after the completion of both antibiotic courses, she developed angioedema and periorbital edema (Figure 1), requiring highdose corticosteroids and antihistamines with a corticosteroid course of prednisone 40 mg daily tapered to 10 mg daily over 12 days and diphenhydramine 25 mg to use up to 4 times daily. Workup for both was acquired and hereditary angioedema was unremarkable. Two months later, the patient developed patches of alopecia, oral ulcerations, and hypopigmented plaques with a peripheral hyperpigmented rim on the central face and bilateral conchal bowls (Figure 2). She also developed hypopigmented papules with peripheral hyperpigmentation on the bilateral dorsal hands overlying the metacarpal and proximal interphalangeal joints, which eventually ulcerated (Figure 3). Laboratory evaluation, including tests for creatine kinase, aldolase, transaminases, lactate dehydrogenase, and autoantibodies (antiJo-1, anti-Mi-2, anti-MDA-5, anti-TIF-1, anti-NXP-2, and anti-SAEP), were unremarkable. A punch biopsy from a papule on the right dorsal hand showed superficial perivascular lymphohistiocytic inflammation with a subtle focal increase in dermal mucin, highlighted by the colloidal iron stain. Further evaluation of the left breast plaque revealed ER/PR+ HER2- stage IIIB inflammatory breast cancer.

DISCUSSION

Based on the clinical presentation and diagnosis of inflammatory breast cancer, the patient was diagnosed with paraneoplastic clinically amyopathic dermatomyositis (CADM). She was treated for her breast cancer with an initial chemotherapy regimen consisting of dose-dense cyclophosphamide and doxorubicin followed by paclitaxel. The patient underwent a mastectomy, axillary lymph node dissection, and 25 sessions of radiation therapy, and is currently continuing therapy with anastrozole 1 mg daily and ovarian suppression with leuprorelin 11.25 mg every 3 months. For the severe angioedema and dermatomyositis-like cutaneous findings, the patient was continued on high-dose corticosteroids at prednisone 60 mg daily with a prolonged taper to prednisone 10 mg daily. After about 10 months, she transitioned from prednisone 10 mg daily to hydrocortisone 30 mg daily and is currently tapering her hydrocortisone dosing. She was additionally started on monthly intravenous immunoglobulin, hydroxychloroquine 300 mg daily, and amlodipine 5 mg daily. The ulcerated papules on her hands were treated with topical clobetasol 0.05% ointment applied daily, topical tacrolimus 0.1% ointment applied daily, and multiple intralesional triamcinolone 5 mg/mL injections. With this regimen, the patient experienced significant improvement in her cutaneous symptoms.

CADM is a rare autoimmune inflammatory disease featuring classic dermatomyositis-like cutaneous findings such as a heliotrope rash and Gottron papules. Ulcerative Gottron papules are less common than the typical erythematous papules and are associated more strongly with amyopathic disease.1 Paraneoplastic myositis poses a diagnostic challenge because it presents like an idiopathic dermatomyositis and often has a heterogeneous clinical presentation with additional manifestations, including periorbital edema, myalgias, dysphagia, and shortness of breath. If clinically suspected, laboratory tests (eg, creatine kinase, aldolase, transaminases, and lactate dehydrogenase) can assist in diagnosing paraneoplastic myositis. Additionally, serologic testing for autoantibodies such as anti-CADM-140, anti-Jo-1, anti-Mi-2, antiMDA-5, anti-TIF-1, anti-NXP-2, and antiSAE can assist the diagnosis and predict disease phenotype.^1,2

Malignancy can precede, occur during, or develop after the diagnosis of CADM.³ Malignancies most often associated with CADM include ovarian, breast, and lung cancers.⁴ Despite the strong correlation with malignancy, there are currently no screening guidelines for malignancy upon inflammatory myositis diagnosis. Therefore, it is important to consider the entirety of a patient’s clinical presentation in establishing further evaluation in the initial diagnostic workup.

There are numerous systemic complications associated with inflammatory myositis and imaging modalities can help to rule out some of these conditions. CADM is strongly associated with the development of interstitial lung disease, so chest radiography and pulmonary function testing are often checked.¹ Though cardiac and esophageal involvement are more commonly associated with classic dermatomyositis, it may be useful to obtain an electrocardiogram to rule out conduction abnormalities from myocardial involvement, along with esophageal manometry to evaluate for esophageal dysmotility.^1,5

In the management of paraneoplastic CADM, the underlying malignancy should be treated first.⁶ If symptoms persist after the cancer is in remission, then CADM is treated with immunosuppressive medications such as methotrexate, mycophenolate mofetil, or azathioprine. Physical therapy can also provide further symptom relief for those suffering from proximal weakness.

CONCLUSIONS

Presumed mastitis, angioedema, and eczematous lesions for this patient were dermatologic manifestations of an underlying inflammatory breast cancer. This case highlights the importance of early recognition, the diagnosis of CADM and awareness of its association with underlying malignancy, especially within the primary care setting where most skin concerns are addressed. Early clinical suspicion and a swift diagnostic workup can further optimize multidisciplinary management, which is often required to treat malignancies.

A previously healthy 31-year-old female active-duty Navy sailor working as a calibration technician developed a painful, erythematous, pruritic, indurated plaque on her left breast. The sailor was not lactating and had no known family history of malignancy. Initially, she was treated by her primary care practitioner for presumed mastitis with oral cephalexin and then with oral clindamycin with no symptom improvement. About 2 weeks after the completion of both antibiotic courses, she developed angioedema and periorbital edema (Figure 1), requiring highdose corticosteroids and antihistamines with a corticosteroid course of prednisone 40 mg daily tapered to 10 mg daily over 12 days and diphenhydramine 25 mg to use up to 4 times daily. Workup for both was acquired and hereditary angioedema was unremarkable. Two months later, the patient developed patches of alopecia, oral ulcerations, and hypopigmented plaques with a peripheral hyperpigmented rim on the central face and bilateral conchal bowls (Figure 2). She also developed hypopigmented papules with peripheral hyperpigmentation on the bilateral dorsal hands overlying the metacarpal and proximal interphalangeal joints, which eventually ulcerated (Figure 3). Laboratory evaluation, including tests for creatine kinase, aldolase, transaminases, lactate dehydrogenase, and autoantibodies (antiJo-1, anti-Mi-2, anti-MDA-5, anti-TIF-1, anti-NXP-2, and anti-SAEP), were unremarkable. A punch biopsy from a papule on the right dorsal hand showed superficial perivascular lymphohistiocytic inflammation with a subtle focal increase in dermal mucin, highlighted by the colloidal iron stain. Further evaluation of the left breast plaque revealed ER/PR+ HER2- stage IIIB inflammatory breast cancer.

DISCUSSION

Based on the clinical presentation and diagnosis of inflammatory breast cancer, the patient was diagnosed with paraneoplastic clinically amyopathic dermatomyositis (CADM). She was treated for her breast cancer with an initial chemotherapy regimen consisting of dose-dense cyclophosphamide and doxorubicin followed by paclitaxel. The patient underwent a mastectomy, axillary lymph node dissection, and 25 sessions of radiation therapy, and is currently continuing therapy with anastrozole 1 mg daily and ovarian suppression with leuprorelin 11.25 mg every 3 months. For the severe angioedema and dermatomyositis-like cutaneous findings, the patient was continued on high-dose corticosteroids at prednisone 60 mg daily with a prolonged taper to prednisone 10 mg daily. After about 10 months, she transitioned from prednisone 10 mg daily to hydrocortisone 30 mg daily and is currently tapering her hydrocortisone dosing. She was additionally started on monthly intravenous immunoglobulin, hydroxychloroquine 300 mg daily, and amlodipine 5 mg daily. The ulcerated papules on her hands were treated with topical clobetasol 0.05% ointment applied daily, topical tacrolimus 0.1% ointment applied daily, and multiple intralesional triamcinolone 5 mg/mL injections. With this regimen, the patient experienced significant improvement in her cutaneous symptoms.

CADM is a rare autoimmune inflammatory disease featuring classic dermatomyositis-like cutaneous findings such as a heliotrope rash and Gottron papules. Ulcerative Gottron papules are less common than the typical erythematous papules and are associated more strongly with amyopathic disease.1 Paraneoplastic myositis poses a diagnostic challenge because it presents like an idiopathic dermatomyositis and often has a heterogeneous clinical presentation with additional manifestations, including periorbital edema, myalgias, dysphagia, and shortness of breath. If clinically suspected, laboratory tests (eg, creatine kinase, aldolase, transaminases, and lactate dehydrogenase) can assist in diagnosing paraneoplastic myositis. Additionally, serologic testing for autoantibodies such as anti-CADM-140, anti-Jo-1, anti-Mi-2, antiMDA-5, anti-TIF-1, anti-NXP-2, and antiSAE can assist the diagnosis and predict disease phenotype.^1,2

Malignancy can precede, occur during, or develop after the diagnosis of CADM.³ Malignancies most often associated with CADM include ovarian, breast, and lung cancers.⁴ Despite the strong correlation with malignancy, there are currently no screening guidelines for malignancy upon inflammatory myositis diagnosis. Therefore, it is important to consider the entirety of a patient’s clinical presentation in establishing further evaluation in the initial diagnostic workup.

There are numerous systemic complications associated with inflammatory myositis and imaging modalities can help to rule out some of these conditions. CADM is strongly associated with the development of interstitial lung disease, so chest radiography and pulmonary function testing are often checked.¹ Though cardiac and esophageal involvement are more commonly associated with classic dermatomyositis, it may be useful to obtain an electrocardiogram to rule out conduction abnormalities from myocardial involvement, along with esophageal manometry to evaluate for esophageal dysmotility.^1,5

In the management of paraneoplastic CADM, the underlying malignancy should be treated first.⁶ If symptoms persist after the cancer is in remission, then CADM is treated with immunosuppressive medications such as methotrexate, mycophenolate mofetil, or azathioprine. Physical therapy can also provide further symptom relief for those suffering from proximal weakness.

CONCLUSIONS

Presumed mastitis, angioedema, and eczematous lesions for this patient were dermatologic manifestations of an underlying inflammatory breast cancer. This case highlights the importance of early recognition, the diagnosis of CADM and awareness of its association with underlying malignancy, especially within the primary care setting where most skin concerns are addressed. Early clinical suspicion and a swift diagnostic workup can further optimize multidisciplinary management, which is often required to treat malignancies.

A previously healthy 31-year-old female active-duty Navy sailor working as a calibration technician developed a painful, erythematous, pruritic, indurated plaque on her left breast. The sailor was not lactating and had no known family history of malignancy. Initially, she was treated by her primary care practitioner for presumed mastitis with oral cephalexin and then with oral clindamycin with no symptom improvement. About 2 weeks after the completion of both antibiotic courses, she developed angioedema and periorbital edema (Figure 1), requiring highdose corticosteroids and antihistamines with a corticosteroid course of prednisone 40 mg daily tapered to 10 mg daily over 12 days and diphenhydramine 25 mg to use up to 4 times daily. Workup for both was acquired and hereditary angioedema was unremarkable. Two months later, the patient developed patches of alopecia, oral ulcerations, and hypopigmented plaques with a peripheral hyperpigmented rim on the central face and bilateral conchal bowls (Figure 2). She also developed hypopigmented papules with peripheral hyperpigmentation on the bilateral dorsal hands overlying the metacarpal and proximal interphalangeal joints, which eventually ulcerated (Figure 3). Laboratory evaluation, including tests for creatine kinase, aldolase, transaminases, lactate dehydrogenase, and autoantibodies (antiJo-1, anti-Mi-2, anti-MDA-5, anti-TIF-1, anti-NXP-2, and anti-SAEP), were unremarkable. A punch biopsy from a papule on the right dorsal hand showed superficial perivascular lymphohistiocytic inflammation with a subtle focal increase in dermal mucin, highlighted by the colloidal iron stain. Further evaluation of the left breast plaque revealed ER/PR+ HER2- stage IIIB inflammatory breast cancer.

DISCUSSION

Based on the clinical presentation and diagnosis of inflammatory breast cancer, the patient was diagnosed with paraneoplastic clinically amyopathic dermatomyositis (CADM). She was treated for her breast cancer with an initial chemotherapy regimen consisting of dose-dense cyclophosphamide and doxorubicin followed by paclitaxel. The patient underwent a mastectomy, axillary lymph node dissection, and 25 sessions of radiation therapy, and is currently continuing therapy with anastrozole 1 mg daily and ovarian suppression with leuprorelin 11.25 mg every 3 months. For the severe angioedema and dermatomyositis-like cutaneous findings, the patient was continued on high-dose corticosteroids at prednisone 60 mg daily with a prolonged taper to prednisone 10 mg daily. After about 10 months, she transitioned from prednisone 10 mg daily to hydrocortisone 30 mg daily and is currently tapering her hydrocortisone dosing. She was additionally started on monthly intravenous immunoglobulin, hydroxychloroquine 300 mg daily, and amlodipine 5 mg daily. The ulcerated papules on her hands were treated with topical clobetasol 0.05% ointment applied daily, topical tacrolimus 0.1% ointment applied daily, and multiple intralesional triamcinolone 5 mg/mL injections. With this regimen, the patient experienced significant improvement in her cutaneous symptoms.

CADM is a rare autoimmune inflammatory disease featuring classic dermatomyositis-like cutaneous findings such as a heliotrope rash and Gottron papules. Ulcerative Gottron papules are less common than the typical erythematous papules and are associated more strongly with amyopathic disease.1 Paraneoplastic myositis poses a diagnostic challenge because it presents like an idiopathic dermatomyositis and often has a heterogeneous clinical presentation with additional manifestations, including periorbital edema, myalgias, dysphagia, and shortness of breath. If clinically suspected, laboratory tests (eg, creatine kinase, aldolase, transaminases, and lactate dehydrogenase) can assist in diagnosing paraneoplastic myositis. Additionally, serologic testing for autoantibodies such as anti-CADM-140, anti-Jo-1, anti-Mi-2, antiMDA-5, anti-TIF-1, anti-NXP-2, and antiSAE can assist the diagnosis and predict disease phenotype.^1,2

Malignancy can precede, occur during, or develop after the diagnosis of CADM.³ Malignancies most often associated with CADM include ovarian, breast, and lung cancers.⁴ Despite the strong correlation with malignancy, there are currently no screening guidelines for malignancy upon inflammatory myositis diagnosis. Therefore, it is important to consider the entirety of a patient’s clinical presentation in establishing further evaluation in the initial diagnostic workup.

There are numerous systemic complications associated with inflammatory myositis and imaging modalities can help to rule out some of these conditions. CADM is strongly associated with the development of interstitial lung disease, so chest radiography and pulmonary function testing are often checked.¹ Though cardiac and esophageal involvement are more commonly associated with classic dermatomyositis, it may be useful to obtain an electrocardiogram to rule out conduction abnormalities from myocardial involvement, along with esophageal manometry to evaluate for esophageal dysmotility.^1,5

In the management of paraneoplastic CADM, the underlying malignancy should be treated first.⁶ If symptoms persist after the cancer is in remission, then CADM is treated with immunosuppressive medications such as methotrexate, mycophenolate mofetil, or azathioprine. Physical therapy can also provide further symptom relief for those suffering from proximal weakness.

CONCLUSIONS

Presumed mastitis, angioedema, and eczematous lesions for this patient were dermatologic manifestations of an underlying inflammatory breast cancer. This case highlights the importance of early recognition, the diagnosis of CADM and awareness of its association with underlying malignancy, especially within the primary care setting where most skin concerns are addressed. Early clinical suspicion and a swift diagnostic workup can further optimize multidisciplinary management, which is often required to treat malignancies.

Case Presentation: A 65-year-old male veteran presented to the Veterans Affairs Boston Healthcare System (VABHS) emergency department with progressive fatigue, dyspnea on exertion, lightheadedness, and falls over the last month. New bilateral lower extremity numbness up to his knees developed in the week prior to admission and prompted him to seek care. Additional history included 2 episodes of transient loss of consciousness resulting in falls and a week of diarrhea, which had resolved. His medical history was notable for hypothyroidism secondary to Hashimoto thyroiditis, seizure disorder, vitiligo, treated hepatitis C virus (HCV) infection, alcohol use disorder in remission, diabetes mellitus, posttraumatic stress disorder, and traumatic brain injury. His medications included levothyroxine and carbamazepine. He previously worked as a barber but recently had stopped due to cognitive impairment. On initial evaluation, the patient's vital signs included a temperature of 36.3 °C, heart rate of 77 beats per minute, blood pressure of 139/83 mm Hg, respiratory rate of 18 breaths per minute, and 99% oxygen saturation while breathing ambient air. Physical examination was notable for a frail-appearing man in no acute distress. His conjunctivae were pale, and cardiac auscultation revealed a normal heart rate and irregularly irregular heart rhythm. A neurologic examination revealed decreased vibratory sensation in both feet, delayed and minimal speech, and a blunted affect. His skin was warm and dry with patchy hypopigmentation across the face and forehead. Laboratory results are shown in the Table. Testing 2 years previously found the patient's hemoglobin to be 11.4 g/dL and serum creatinine to be 1.7 mg/dL. A peripheral blood smear showed anisocytosis, hypochromia, decreased platelets, ovalocytes, elliptocytes, and rare teardrop cells, with no schistocytes present. Chest radiography and computed tomography of the head were unremarkable. An abdominal ultrasound revealed a complex hypoechoic mass with peripheral rim vascularity in the right hepatic lobe measuring 3.9 cm × 3.6 cm × 3.9 cm.

Lindsey Ulin, MD, Chief Medical Resident, VABHS and Brigham and Women’s Hospital (BWH):

To build the initial differential diagnosis, we are joined today by 3 internal medicine residents who were not involved in the care of this patient. Dr. Hickey, Dr. Ross and Dr. Manivannan, how did you approach this case?

Meghan Hickey, MD, Senior Internal Medicine Resident, VABHS and Boston Medical Center (BMC):

The constellation of fatigue, weakness, blunted affect, and delayed, minimal speech suggested central nervous system involvement, which I sought to unify with hemolytic anemia and his liver mass. The first diagnosis I considered was Wilson disease; however, this genetic disorder of copper metabolism often presents with liver failure or cirrhosis in young or middle-aged women, so this presentation would be atypical. Next, given the hypopigmentation was reported only on sun-exposed areas of the patient’s face, I considered possibilities other than vitiligo to avoid diagnostic anchoring. One such alternate diagnosis is porphyria cutanea tarda (PCT), which presents in middle-aged and older adults with a photosensitive dermatitis that can include acute sensory deficits. Manifestations of PCT can be triggered by alcohol consumption, though his alcohol use disorder was thought to be in remission, as well as HCV, for which he previously received treatment. However, anemia is uncommon in PCT, so the patient’s low hemoglobin would not be explained by this diagnosis. Lastly, I considered thrombotic thrombocytopenic purpura (TTP) given his anemia, thrombocytopenia, and neurologic symptoms; however, the patient did not have fever or a clear inciting cause, his renal dysfunction was relatively mild, and the peripheral blood smear revealed no schistocytes, which should be present in TTP.

Caroline Ross, MD, and Alan Manivannan, MD; Senior Internal Medicine Residents, VABHS and BMC:

We noted several salient features in the history and physical examination. First, we sought to explain the bilateral lower extremity numbness and decreased vibratory sensation in the feet leading to falls. We also considered his anemia and thrombocytopenia with signs of hemolysis including elevated lactate dehydrogenase (LDH), low haptoglobin, and elevated total bilirubin; however, with normal coagulation parameters. These results initially raised our concern for a thrombotic microangiopathy (TMA) such as TTP. However, the peripheral smear lacked schistocytes, making this less likely. The combination of his neurologic symptoms and TMA-like laboratory findings but without schistocytes raised our concern for vitamin B12 deficiency. Vitamin B12 deficiency can cause a pseudo-TMA picture with laboratory finding similar to TTP; however, schistocytes are typically absent. We also considered the possibility of hepatocellular carcinoma (HCC) with bone marrow infiltration leading to anemia given the finding of a liver mass on his abdominal ultrasound and low reticulocyte index. However, this would not explain his hemolysis. We also considered chronic disseminated intravascular coagulation in the setting of a malignancy as a contributor, but again, the smear lacked schistocytes and his coagulation parameters were normal. Finally, we considered a primary bone marrow process such as myelodysplastic syndrome due to the bicytopenia with poor bone marrow response and smear with tear drop cells and elliptocytes. However, we felt this was less likely as this would not explain his hemolytic anemia.

Dr. Ulin:

To refine the differential diagnosis, we are joined by an expert clinician who was also not involved in the care of this patient to describe his approach to this case. Dr. Orlander, can you walk us through your clinical reasoning?

Jay Orlander, MD, MPH: Professor of Medicine, Section of General Internal Medicine, Boston University Chobanian & Avedisian School of Medicine, Associate Chief, Medical Service, VABHS:

I will first comment on the hepatic mass. The hypoechoic liver mass with peripheral vascularity suggests a growing tumor. The patient has a history of substance use disorder with alcohol and treated HCV. He remains at increased risk for HCC even after prior successful HCV treatment and has 2 of 4 known risk factors for developing HCC— diabetes mellitus and alcohol use—the other 2 being underlying metabolic dysfunctionassociated steatotic liver disease (MASLD) and the presence of hepatic fibrosis, which we have not yet assessed. Worsening liver function can lead to cognitive issues and alcohol to peripheral neuropathy, but his story is not consistent with this. For his liver mass, I recommend a nonurgent magnetic resonance image for further evaluation.

Next, let’s consider his markedly elevated thyrotropin (TSH). Cognitive impairment along with lethargy, fatigue, and decreased exercise tolerance can be prominent features in severe hypothyroidism, but this diagnosis would not explain his hematologic findings.¹

I view the principal finding of his laboratory testing as being that his bone marrow is failing to maintain adequate blood elements. He has a markedly low hematocrit along with low platelets and low-normal white blood cell counts. There is an absence of schistocytes on the blood smear, and after correcting his reticulocyte count for his degree of anemia (observed reticulocyte percentage [0.8%] x observed hematocrit [15.3%] / expected hematocrit [40%]), results in a reticulocyte index of 0.12, which is low. This suggests his bone marrow is failing to manufacture red blood cells at an appropriate rate. His haptoglobin is unmeasurable, so there is some free heme circulating. Hence, I infer that hemolysis and ineffective erythropoiesis are both occurring within the bone marrow, which also explains the slight elevation in bilirubin.

Intramedullary hemolysis with a markedly elevated LDH can be seen in severe vitamin B₁₂ deficiency, which has many causes, but one cause in particular warrants consideration in this case: pernicious anemia. Pernicious anemia has an overall prevalence of about 0.1%, but is more common in older adults, and is estimated to be present in 2% to 3% of adults aged > 65 years.² Prevalence is also increased in patients with other autoimmune diseases such as vitiligo and hypothyroidism, which our patient has.³ The pathophysiology of pernicious anemia relates to either autoimmune gastric parietal cell destruction and/or the development of antibodies against intrinsic factor, which is required for absorption of vitamin B₁₂. Early disease may present with macrocytosis and a normal hemoglobin initially, but anemia develops over time if left untreated. When the primary cause of pernicious anemia is gastric parietal cell destruction, there is also an associated lack of stomach acid production (achlorhydria) with resulting poor micronutrient absorption; specifically, vitamin D, vitamin C, and iron. Hence, 30% of patients diagnosed with pernicious anemia have concurrent iron deficiency, which may counteract macrocytosis and result in a normal mean corpuscular volume. 4 Some medications are also poorly absorbed in achlorhydric states, such as levothyroxine, and treatment doses need to be increased, which could explain his markedly elevated TSH despite presumed medication adherence.

Vitamin B₁₂ is essential for both the peripheral and central nervous systems. Longstanding severe B₁₂ deficiency can explain all of his neurological and neurocognitive changes. The most common neurologic findings in B₁₂ deficiency are symmetric paresthesias or numbness and gait problems. The sensory neuropathy affects the lower extremities more commonly than the upper. Untreated, patients can develop progressive weakness, ataxia, and orthostatic hypotension with syncope, as well as neuropsychiatric changes including depression or mood impairment, cognitive slowing, forgetfulness, and dementia.

Dr. Ulin:

Dr. Orlander, which pieces of objective data are most important in forming your differential diagnosis, and what tests would you obtain next?

Dr. Orlander:

The 3 most salient laboratory tests to me are a complete blood count, with all cell lines impacted but the hemoglobin and hematocrit most dramatically impacted, reticulocyte count of 0.8%, which is inappropriately low and hence suggests a hypoproliferative anemia, and the elevated LDH > 5000 IU/L.

Since my suspected diagnosis is pernicious anemia, I would obtain a blood smear looking for hypersegmented neutrophils, > 1 white blood cells with 5 lobes, or 1 with 6 lobes, which should clinch the diagnosis. Methylmalonic acid (MMA) levels are the most sensitive test for B₁₂ deficiency, so I would also obtain that. Finally, I would check a B₁₂ level, since in a patient with pernicious anemia, I would expect the level to be < 200 pg/mL.

Dr. Ulin:

Before we reveal the results of the patient’s additional workup, how do you approach interpreting B₁₂ levels?

Dr. Orlander:

Measuring B12 can sometimes be problematic: the normal range is considered 200 to 900 pg/mL, but patients with measured low-normal levels in the range of 200 to 400 pg/mL can actually be physiologically deficient. There are also several common causes of falsely low and falsely high B₁₂ levels in the absence of B₁₂ deficiency. Hence, for patients with mild symptoms that could be due to B₁₂ deficiency, many clinicians choose to just treat with B₁₂ supplementation, deeming it safer to treat than miss an early diagnosis. B₁₂ is involved in hydrogen transfer to convert MMA into succinyl-CoA and hence true vitamin B₁₂ deficiency causes an increase in MMA.

Decreased production of vitamin B12 binding proteins, like haptocorrin, has been proposed as the mechanism for spurious low values.⁵ Certain conditions or medications can also cause spurious low serum vitamin B₁₂ levels and thus might cause the appearance of vitamin B₁₂ deficiency when the patient is not deficient. Examples include multiple myeloma, HIV infection, pregnancy, oral contraceptives, and phenytoin use. An example of spuriously low vitamin B₁₂ level in pregnancy was demonstrated in a series of 50 pregnant individuals with low vitamin B₁₂ levels (45-199 pg/mL), in whom metabolite testing for MMA and homocysteine showed no correlation with vitamin B₁₂ level.⁶

Further complicating things, some conditions can cause spuriously increased vitamin B₁₂ levels and thus might cause the appearance of normal vitamin B₁₂ levels when the patient is actually deficient.⁷ Examples include occult malignancy, myeloproliferative neoplasms, alcoholic liver disease, kidney disease, and nitrous oxide exposure (the latter of which is unique in that it can also cause true vitamin B₁₂ deficiency, as evidenced by clinical symptoms and high MMA levels).^8,9

Lastly, autoantibodies to intrinsic factor in individuals with pernicious anemia may compete with intrinsic factor in the chemiluminescence assay and result in spuriously normal vitamin B₁₂ levels in the presence of true deficiency.^10-12 If the vitamin B₁₂ level is very high (eg, 800 pg/mL), we do not worry about this effect in the absence of clinical features suggesting vitamin B₁₂ deficiency; however, if the vitamin B₁₂ level is borderline or low-normal and/or other clinical features suggest vitamin B₁₂ deficiency, it is prudent to obtain other testing such as an MMA level.

Dr. Ulin:

We are also joined by Dr. Rahul Ganatra, who cared for the patient at the time the diagnosis was made. Dr. Ganatra, can you share the final diagnosis and provide an update on the patient?

Rahul Ganatra, MD, MPH, Director of Continuing Medical Education, VABHS:

The patient’s hemoglobin rose to 6.9 g/dL after transfusion of 2 units of packed red blood cells, and his dyspnea on exertion and fatigue improved. Iron studies, serum thiamine, serum folate, ADAMTS13 activity levels, and AM cortisol level were normal. Upon closer examination of the peripheral blood smear, rare hypersegmented neutrophils were noted. Serum B₁₂ level returned below assay (< 146 pg/mL), and serum MMA was 50,800 nmol/L, confirming the diagnosis of severe vitamin B₁₂ deficiency. Antibodies against intrinsic factor were detected, confirming the diagnosis of pernicious anemia. Treatment was initiated with intramuscular cyanocobalamin every other day and was transitioned to weekly dosing at the time of hospital discharge. After excluding adrenal insufficiency, his levothyroxine dose was increased. Finally, a liver mass biopsy confirmed a concomitant diagnosis of HCC. The patient was discharged home. Five weeks after discharge, his serum B₁₂ level rose to > 1000 pg/mL, and 10 months after discharge, his TSH fell to 0.97 uIU/mL. Several months later, he underwent stereotactic body radiotherapy for the HCC. One year after his initial presentation, he has not resumed work as a barber.

Case Presentation: A 65-year-old male veteran presented to the Veterans Affairs Boston Healthcare System (VABHS) emergency department with progressive fatigue, dyspnea on exertion, lightheadedness, and falls over the last month. New bilateral lower extremity numbness up to his knees developed in the week prior to admission and prompted him to seek care. Additional history included 2 episodes of transient loss of consciousness resulting in falls and a week of diarrhea, which had resolved. His medical history was notable for hypothyroidism secondary to Hashimoto thyroiditis, seizure disorder, vitiligo, treated hepatitis C virus (HCV) infection, alcohol use disorder in remission, diabetes mellitus, posttraumatic stress disorder, and traumatic brain injury. His medications included levothyroxine and carbamazepine. He previously worked as a barber but recently had stopped due to cognitive impairment. On initial evaluation, the patient's vital signs included a temperature of 36.3 °C, heart rate of 77 beats per minute, blood pressure of 139/83 mm Hg, respiratory rate of 18 breaths per minute, and 99% oxygen saturation while breathing ambient air. Physical examination was notable for a frail-appearing man in no acute distress. His conjunctivae were pale, and cardiac auscultation revealed a normal heart rate and irregularly irregular heart rhythm. A neurologic examination revealed decreased vibratory sensation in both feet, delayed and minimal speech, and a blunted affect. His skin was warm and dry with patchy hypopigmentation across the face and forehead. Laboratory results are shown in the Table. Testing 2 years previously found the patient's hemoglobin to be 11.4 g/dL and serum creatinine to be 1.7 mg/dL. A peripheral blood smear showed anisocytosis, hypochromia, decreased platelets, ovalocytes, elliptocytes, and rare teardrop cells, with no schistocytes present. Chest radiography and computed tomography of the head were unremarkable. An abdominal ultrasound revealed a complex hypoechoic mass with peripheral rim vascularity in the right hepatic lobe measuring 3.9 cm × 3.6 cm × 3.9 cm.

Lindsey Ulin, MD, Chief Medical Resident, VABHS and Brigham and Women’s Hospital (BWH):

To build the initial differential diagnosis, we are joined today by 3 internal medicine residents who were not involved in the care of this patient. Dr. Hickey, Dr. Ross and Dr. Manivannan, how did you approach this case?

Meghan Hickey, MD, Senior Internal Medicine Resident, VABHS and Boston Medical Center (BMC):

The constellation of fatigue, weakness, blunted affect, and delayed, minimal speech suggested central nervous system involvement, which I sought to unify with hemolytic anemia and his liver mass. The first diagnosis I considered was Wilson disease; however, this genetic disorder of copper metabolism often presents with liver failure or cirrhosis in young or middle-aged women, so this presentation would be atypical. Next, given the hypopigmentation was reported only on sun-exposed areas of the patient’s face, I considered possibilities other than vitiligo to avoid diagnostic anchoring. One such alternate diagnosis is porphyria cutanea tarda (PCT), which presents in middle-aged and older adults with a photosensitive dermatitis that can include acute sensory deficits. Manifestations of PCT can be triggered by alcohol consumption, though his alcohol use disorder was thought to be in remission, as well as HCV, for which he previously received treatment. However, anemia is uncommon in PCT, so the patient’s low hemoglobin would not be explained by this diagnosis. Lastly, I considered thrombotic thrombocytopenic purpura (TTP) given his anemia, thrombocytopenia, and neurologic symptoms; however, the patient did not have fever or a clear inciting cause, his renal dysfunction was relatively mild, and the peripheral blood smear revealed no schistocytes, which should be present in TTP.

Caroline Ross, MD, and Alan Manivannan, MD; Senior Internal Medicine Residents, VABHS and BMC:

We noted several salient features in the history and physical examination. First, we sought to explain the bilateral lower extremity numbness and decreased vibratory sensation in the feet leading to falls. We also considered his anemia and thrombocytopenia with signs of hemolysis including elevated lactate dehydrogenase (LDH), low haptoglobin, and elevated total bilirubin; however, with normal coagulation parameters. These results initially raised our concern for a thrombotic microangiopathy (TMA) such as TTP. However, the peripheral smear lacked schistocytes, making this less likely. The combination of his neurologic symptoms and TMA-like laboratory findings but without schistocytes raised our concern for vitamin B12 deficiency. Vitamin B12 deficiency can cause a pseudo-TMA picture with laboratory finding similar to TTP; however, schistocytes are typically absent. We also considered the possibility of hepatocellular carcinoma (HCC) with bone marrow infiltration leading to anemia given the finding of a liver mass on his abdominal ultrasound and low reticulocyte index. However, this would not explain his hemolysis. We also considered chronic disseminated intravascular coagulation in the setting of a malignancy as a contributor, but again, the smear lacked schistocytes and his coagulation parameters were normal. Finally, we considered a primary bone marrow process such as myelodysplastic syndrome due to the bicytopenia with poor bone marrow response and smear with tear drop cells and elliptocytes. However, we felt this was less likely as this would not explain his hemolytic anemia.

Dr. Ulin:

To refine the differential diagnosis, we are joined by an expert clinician who was also not involved in the care of this patient to describe his approach to this case. Dr. Orlander, can you walk us through your clinical reasoning?

Jay Orlander, MD, MPH: Professor of Medicine, Section of General Internal Medicine, Boston University Chobanian & Avedisian School of Medicine, Associate Chief, Medical Service, VABHS:

I will first comment on the hepatic mass. The hypoechoic liver mass with peripheral vascularity suggests a growing tumor. The patient has a history of substance use disorder with alcohol and treated HCV. He remains at increased risk for HCC even after prior successful HCV treatment and has 2 of 4 known risk factors for developing HCC— diabetes mellitus and alcohol use—the other 2 being underlying metabolic dysfunctionassociated steatotic liver disease (MASLD) and the presence of hepatic fibrosis, which we have not yet assessed. Worsening liver function can lead to cognitive issues and alcohol to peripheral neuropathy, but his story is not consistent with this. For his liver mass, I recommend a nonurgent magnetic resonance image for further evaluation.

Next, let’s consider his markedly elevated thyrotropin (TSH). Cognitive impairment along with lethargy, fatigue, and decreased exercise tolerance can be prominent features in severe hypothyroidism, but this diagnosis would not explain his hematologic findings.¹

I view the principal finding of his laboratory testing as being that his bone marrow is failing to maintain adequate blood elements. He has a markedly low hematocrit along with low platelets and low-normal white blood cell counts. There is an absence of schistocytes on the blood smear, and after correcting his reticulocyte count for his degree of anemia (observed reticulocyte percentage [0.8%] x observed hematocrit [15.3%] / expected hematocrit [40%]), results in a reticulocyte index of 0.12, which is low. This suggests his bone marrow is failing to manufacture red blood cells at an appropriate rate. His haptoglobin is unmeasurable, so there is some free heme circulating. Hence, I infer that hemolysis and ineffective erythropoiesis are both occurring within the bone marrow, which also explains the slight elevation in bilirubin.

Intramedullary hemolysis with a markedly elevated LDH can be seen in severe vitamin B₁₂ deficiency, which has many causes, but one cause in particular warrants consideration in this case: pernicious anemia. Pernicious anemia has an overall prevalence of about 0.1%, but is more common in older adults, and is estimated to be present in 2% to 3% of adults aged > 65 years.² Prevalence is also increased in patients with other autoimmune diseases such as vitiligo and hypothyroidism, which our patient has.³ The pathophysiology of pernicious anemia relates to either autoimmune gastric parietal cell destruction and/or the development of antibodies against intrinsic factor, which is required for absorption of vitamin B₁₂. Early disease may present with macrocytosis and a normal hemoglobin initially, but anemia develops over time if left untreated. When the primary cause of pernicious anemia is gastric parietal cell destruction, there is also an associated lack of stomach acid production (achlorhydria) with resulting poor micronutrient absorption; specifically, vitamin D, vitamin C, and iron. Hence, 30% of patients diagnosed with pernicious anemia have concurrent iron deficiency, which may counteract macrocytosis and result in a normal mean corpuscular volume. 4 Some medications are also poorly absorbed in achlorhydric states, such as levothyroxine, and treatment doses need to be increased, which could explain his markedly elevated TSH despite presumed medication adherence.

Vitamin B₁₂ is essential for both the peripheral and central nervous systems. Longstanding severe B₁₂ deficiency can explain all of his neurological and neurocognitive changes. The most common neurologic findings in B₁₂ deficiency are symmetric paresthesias or numbness and gait problems. The sensory neuropathy affects the lower extremities more commonly than the upper. Untreated, patients can develop progressive weakness, ataxia, and orthostatic hypotension with syncope, as well as neuropsychiatric changes including depression or mood impairment, cognitive slowing, forgetfulness, and dementia.

Dr. Ulin:

Dr. Orlander, which pieces of objective data are most important in forming your differential diagnosis, and what tests would you obtain next?

Dr. Orlander:

The 3 most salient laboratory tests to me are a complete blood count, with all cell lines impacted but the hemoglobin and hematocrit most dramatically impacted, reticulocyte count of 0.8%, which is inappropriately low and hence suggests a hypoproliferative anemia, and the elevated LDH > 5000 IU/L.

Since my suspected diagnosis is pernicious anemia, I would obtain a blood smear looking for hypersegmented neutrophils, > 1 white blood cells with 5 lobes, or 1 with 6 lobes, which should clinch the diagnosis. Methylmalonic acid (MMA) levels are the most sensitive test for B₁₂ deficiency, so I would also obtain that. Finally, I would check a B₁₂ level, since in a patient with pernicious anemia, I would expect the level to be < 200 pg/mL.

Dr. Ulin:

Before we reveal the results of the patient’s additional workup, how do you approach interpreting B₁₂ levels?

Dr. Orlander:

Measuring B12 can sometimes be problematic: the normal range is considered 200 to 900 pg/mL, but patients with measured low-normal levels in the range of 200 to 400 pg/mL can actually be physiologically deficient. There are also several common causes of falsely low and falsely high B₁₂ levels in the absence of B₁₂ deficiency. Hence, for patients with mild symptoms that could be due to B₁₂ deficiency, many clinicians choose to just treat with B₁₂ supplementation, deeming it safer to treat than miss an early diagnosis. B₁₂ is involved in hydrogen transfer to convert MMA into succinyl-CoA and hence true vitamin B₁₂ deficiency causes an increase in MMA.

Decreased production of vitamin B12 binding proteins, like haptocorrin, has been proposed as the mechanism for spurious low values.⁵ Certain conditions or medications can also cause spurious low serum vitamin B₁₂ levels and thus might cause the appearance of vitamin B₁₂ deficiency when the patient is not deficient. Examples include multiple myeloma, HIV infection, pregnancy, oral contraceptives, and phenytoin use. An example of spuriously low vitamin B₁₂ level in pregnancy was demonstrated in a series of 50 pregnant individuals with low vitamin B₁₂ levels (45-199 pg/mL), in whom metabolite testing for MMA and homocysteine showed no correlation with vitamin B₁₂ level.⁶

Further complicating things, some conditions can cause spuriously increased vitamin B₁₂ levels and thus might cause the appearance of normal vitamin B₁₂ levels when the patient is actually deficient.⁷ Examples include occult malignancy, myeloproliferative neoplasms, alcoholic liver disease, kidney disease, and nitrous oxide exposure (the latter of which is unique in that it can also cause true vitamin B₁₂ deficiency, as evidenced by clinical symptoms and high MMA levels).^8,9

Lastly, autoantibodies to intrinsic factor in individuals with pernicious anemia may compete with intrinsic factor in the chemiluminescence assay and result in spuriously normal vitamin B₁₂ levels in the presence of true deficiency.^10-12 If the vitamin B₁₂ level is very high (eg, 800 pg/mL), we do not worry about this effect in the absence of clinical features suggesting vitamin B₁₂ deficiency; however, if the vitamin B₁₂ level is borderline or low-normal and/or other clinical features suggest vitamin B₁₂ deficiency, it is prudent to obtain other testing such as an MMA level.

Dr. Ulin:

We are also joined by Dr. Rahul Ganatra, who cared for the patient at the time the diagnosis was made. Dr. Ganatra, can you share the final diagnosis and provide an update on the patient?

Rahul Ganatra, MD, MPH, Director of Continuing Medical Education, VABHS:

The patient’s hemoglobin rose to 6.9 g/dL after transfusion of 2 units of packed red blood cells, and his dyspnea on exertion and fatigue improved. Iron studies, serum thiamine, serum folate, ADAMTS13 activity levels, and AM cortisol level were normal. Upon closer examination of the peripheral blood smear, rare hypersegmented neutrophils were noted. Serum B₁₂ level returned below assay (< 146 pg/mL), and serum MMA was 50,800 nmol/L, confirming the diagnosis of severe vitamin B₁₂ deficiency. Antibodies against intrinsic factor were detected, confirming the diagnosis of pernicious anemia. Treatment was initiated with intramuscular cyanocobalamin every other day and was transitioned to weekly dosing at the time of hospital discharge. After excluding adrenal insufficiency, his levothyroxine dose was increased. Finally, a liver mass biopsy confirmed a concomitant diagnosis of HCC. The patient was discharged home. Five weeks after discharge, his serum B₁₂ level rose to > 1000 pg/mL, and 10 months after discharge, his TSH fell to 0.97 uIU/mL. Several months later, he underwent stereotactic body radiotherapy for the HCC. One year after his initial presentation, he has not resumed work as a barber.

Case Presentation: A 65-year-old male veteran presented to the Veterans Affairs Boston Healthcare System (VABHS) emergency department with progressive fatigue, dyspnea on exertion, lightheadedness, and falls over the last month. New bilateral lower extremity numbness up to his knees developed in the week prior to admission and prompted him to seek care. Additional history included 2 episodes of transient loss of consciousness resulting in falls and a week of diarrhea, which had resolved. His medical history was notable for hypothyroidism secondary to Hashimoto thyroiditis, seizure disorder, vitiligo, treated hepatitis C virus (HCV) infection, alcohol use disorder in remission, diabetes mellitus, posttraumatic stress disorder, and traumatic brain injury. His medications included levothyroxine and carbamazepine. He previously worked as a barber but recently had stopped due to cognitive impairment. On initial evaluation, the patient's vital signs included a temperature of 36.3 °C, heart rate of 77 beats per minute, blood pressure of 139/83 mm Hg, respiratory rate of 18 breaths per minute, and 99% oxygen saturation while breathing ambient air. Physical examination was notable for a frail-appearing man in no acute distress. His conjunctivae were pale, and cardiac auscultation revealed a normal heart rate and irregularly irregular heart rhythm. A neurologic examination revealed decreased vibratory sensation in both feet, delayed and minimal speech, and a blunted affect. His skin was warm and dry with patchy hypopigmentation across the face and forehead. Laboratory results are shown in the Table. Testing 2 years previously found the patient's hemoglobin to be 11.4 g/dL and serum creatinine to be 1.7 mg/dL. A peripheral blood smear showed anisocytosis, hypochromia, decreased platelets, ovalocytes, elliptocytes, and rare teardrop cells, with no schistocytes present. Chest radiography and computed tomography of the head were unremarkable. An abdominal ultrasound revealed a complex hypoechoic mass with peripheral rim vascularity in the right hepatic lobe measuring 3.9 cm × 3.6 cm × 3.9 cm.

Lindsey Ulin, MD, Chief Medical Resident, VABHS and Brigham and Women’s Hospital (BWH):

To build the initial differential diagnosis, we are joined today by 3 internal medicine residents who were not involved in the care of this patient. Dr. Hickey, Dr. Ross and Dr. Manivannan, how did you approach this case?

Meghan Hickey, MD, Senior Internal Medicine Resident, VABHS and Boston Medical Center (BMC):

The constellation of fatigue, weakness, blunted affect, and delayed, minimal speech suggested central nervous system involvement, which I sought to unify with hemolytic anemia and his liver mass. The first diagnosis I considered was Wilson disease; however, this genetic disorder of copper metabolism often presents with liver failure or cirrhosis in young or middle-aged women, so this presentation would be atypical. Next, given the hypopigmentation was reported only on sun-exposed areas of the patient’s face, I considered possibilities other than vitiligo to avoid diagnostic anchoring. One such alternate diagnosis is porphyria cutanea tarda (PCT), which presents in middle-aged and older adults with a photosensitive dermatitis that can include acute sensory deficits. Manifestations of PCT can be triggered by alcohol consumption, though his alcohol use disorder was thought to be in remission, as well as HCV, for which he previously received treatment. However, anemia is uncommon in PCT, so the patient’s low hemoglobin would not be explained by this diagnosis. Lastly, I considered thrombotic thrombocytopenic purpura (TTP) given his anemia, thrombocytopenia, and neurologic symptoms; however, the patient did not have fever or a clear inciting cause, his renal dysfunction was relatively mild, and the peripheral blood smear revealed no schistocytes, which should be present in TTP.

Caroline Ross, MD, and Alan Manivannan, MD; Senior Internal Medicine Residents, VABHS and BMC:

We noted several salient features in the history and physical examination. First, we sought to explain the bilateral lower extremity numbness and decreased vibratory sensation in the feet leading to falls. We also considered his anemia and thrombocytopenia with signs of hemolysis including elevated lactate dehydrogenase (LDH), low haptoglobin, and elevated total bilirubin; however, with normal coagulation parameters. These results initially raised our concern for a thrombotic microangiopathy (TMA) such as TTP. However, the peripheral smear lacked schistocytes, making this less likely. The combination of his neurologic symptoms and TMA-like laboratory findings but without schistocytes raised our concern for vitamin B12 deficiency. Vitamin B12 deficiency can cause a pseudo-TMA picture with laboratory finding similar to TTP; however, schistocytes are typically absent. We also considered the possibility of hepatocellular carcinoma (HCC) with bone marrow infiltration leading to anemia given the finding of a liver mass on his abdominal ultrasound and low reticulocyte index. However, this would not explain his hemolysis. We also considered chronic disseminated intravascular coagulation in the setting of a malignancy as a contributor, but again, the smear lacked schistocytes and his coagulation parameters were normal. Finally, we considered a primary bone marrow process such as myelodysplastic syndrome due to the bicytopenia with poor bone marrow response and smear with tear drop cells and elliptocytes. However, we felt this was less likely as this would not explain his hemolytic anemia.

Dr. Ulin:

To refine the differential diagnosis, we are joined by an expert clinician who was also not involved in the care of this patient to describe his approach to this case. Dr. Orlander, can you walk us through your clinical reasoning?

Jay Orlander, MD, MPH: Professor of Medicine, Section of General Internal Medicine, Boston University Chobanian & Avedisian School of Medicine, Associate Chief, Medical Service, VABHS:

I will first comment on the hepatic mass. The hypoechoic liver mass with peripheral vascularity suggests a growing tumor. The patient has a history of substance use disorder with alcohol and treated HCV. He remains at increased risk for HCC even after prior successful HCV treatment and has 2 of 4 known risk factors for developing HCC— diabetes mellitus and alcohol use—the other 2 being underlying metabolic dysfunctionassociated steatotic liver disease (MASLD) and the presence of hepatic fibrosis, which we have not yet assessed. Worsening liver function can lead to cognitive issues and alcohol to peripheral neuropathy, but his story is not consistent with this. For his liver mass, I recommend a nonurgent magnetic resonance image for further evaluation.

Next, let’s consider his markedly elevated thyrotropin (TSH). Cognitive impairment along with lethargy, fatigue, and decreased exercise tolerance can be prominent features in severe hypothyroidism, but this diagnosis would not explain his hematologic findings.¹

I view the principal finding of his laboratory testing as being that his bone marrow is failing to maintain adequate blood elements. He has a markedly low hematocrit along with low platelets and low-normal white blood cell counts. There is an absence of schistocytes on the blood smear, and after correcting his reticulocyte count for his degree of anemia (observed reticulocyte percentage [0.8%] x observed hematocrit [15.3%] / expected hematocrit [40%]), results in a reticulocyte index of 0.12, which is low. This suggests his bone marrow is failing to manufacture red blood cells at an appropriate rate. His haptoglobin is unmeasurable, so there is some free heme circulating. Hence, I infer that hemolysis and ineffective erythropoiesis are both occurring within the bone marrow, which also explains the slight elevation in bilirubin.

Intramedullary hemolysis with a markedly elevated LDH can be seen in severe vitamin B₁₂ deficiency, which has many causes, but one cause in particular warrants consideration in this case: pernicious anemia. Pernicious anemia has an overall prevalence of about 0.1%, but is more common in older adults, and is estimated to be present in 2% to 3% of adults aged > 65 years.² Prevalence is also increased in patients with other autoimmune diseases such as vitiligo and hypothyroidism, which our patient has.³ The pathophysiology of pernicious anemia relates to either autoimmune gastric parietal cell destruction and/or the development of antibodies against intrinsic factor, which is required for absorption of vitamin B₁₂. Early disease may present with macrocytosis and a normal hemoglobin initially, but anemia develops over time if left untreated. When the primary cause of pernicious anemia is gastric parietal cell destruction, there is also an associated lack of stomach acid production (achlorhydria) with resulting poor micronutrient absorption; specifically, vitamin D, vitamin C, and iron. Hence, 30% of patients diagnosed with pernicious anemia have concurrent iron deficiency, which may counteract macrocytosis and result in a normal mean corpuscular volume. 4 Some medications are also poorly absorbed in achlorhydric states, such as levothyroxine, and treatment doses need to be increased, which could explain his markedly elevated TSH despite presumed medication adherence.

Vitamin B₁₂ is essential for both the peripheral and central nervous systems. Longstanding severe B₁₂ deficiency can explain all of his neurological and neurocognitive changes. The most common neurologic findings in B₁₂ deficiency are symmetric paresthesias or numbness and gait problems. The sensory neuropathy affects the lower extremities more commonly than the upper. Untreated, patients can develop progressive weakness, ataxia, and orthostatic hypotension with syncope, as well as neuropsychiatric changes including depression or mood impairment, cognitive slowing, forgetfulness, and dementia.

Dr. Ulin:

Dr. Orlander, which pieces of objective data are most important in forming your differential diagnosis, and what tests would you obtain next?

Dr. Orlander:

The 3 most salient laboratory tests to me are a complete blood count, with all cell lines impacted but the hemoglobin and hematocrit most dramatically impacted, reticulocyte count of 0.8%, which is inappropriately low and hence suggests a hypoproliferative anemia, and the elevated LDH > 5000 IU/L.

Since my suspected diagnosis is pernicious anemia, I would obtain a blood smear looking for hypersegmented neutrophils, > 1 white blood cells with 5 lobes, or 1 with 6 lobes, which should clinch the diagnosis. Methylmalonic acid (MMA) levels are the most sensitive test for B₁₂ deficiency, so I would also obtain that. Finally, I would check a B₁₂ level, since in a patient with pernicious anemia, I would expect the level to be < 200 pg/mL.

Dr. Ulin:

Before we reveal the results of the patient’s additional workup, how do you approach interpreting B₁₂ levels?

Dr. Orlander:

Measuring B12 can sometimes be problematic: the normal range is considered 200 to 900 pg/mL, but patients with measured low-normal levels in the range of 200 to 400 pg/mL can actually be physiologically deficient. There are also several common causes of falsely low and falsely high B₁₂ levels in the absence of B₁₂ deficiency. Hence, for patients with mild symptoms that could be due to B₁₂ deficiency, many clinicians choose to just treat with B₁₂ supplementation, deeming it safer to treat than miss an early diagnosis. B₁₂ is involved in hydrogen transfer to convert MMA into succinyl-CoA and hence true vitamin B₁₂ deficiency causes an increase in MMA.

Decreased production of vitamin B12 binding proteins, like haptocorrin, has been proposed as the mechanism for spurious low values.⁵ Certain conditions or medications can also cause spurious low serum vitamin B₁₂ levels and thus might cause the appearance of vitamin B₁₂ deficiency when the patient is not deficient. Examples include multiple myeloma, HIV infection, pregnancy, oral contraceptives, and phenytoin use. An example of spuriously low vitamin B₁₂ level in pregnancy was demonstrated in a series of 50 pregnant individuals with low vitamin B₁₂ levels (45-199 pg/mL), in whom metabolite testing for MMA and homocysteine showed no correlation with vitamin B₁₂ level.⁶

Further complicating things, some conditions can cause spuriously increased vitamin B₁₂ levels and thus might cause the appearance of normal vitamin B₁₂ levels when the patient is actually deficient.⁷ Examples include occult malignancy, myeloproliferative neoplasms, alcoholic liver disease, kidney disease, and nitrous oxide exposure (the latter of which is unique in that it can also cause true vitamin B₁₂ deficiency, as evidenced by clinical symptoms and high MMA levels).^8,9

Lastly, autoantibodies to intrinsic factor in individuals with pernicious anemia may compete with intrinsic factor in the chemiluminescence assay and result in spuriously normal vitamin B₁₂ levels in the presence of true deficiency.^10-12 If the vitamin B₁₂ level is very high (eg, 800 pg/mL), we do not worry about this effect in the absence of clinical features suggesting vitamin B₁₂ deficiency; however, if the vitamin B₁₂ level is borderline or low-normal and/or other clinical features suggest vitamin B₁₂ deficiency, it is prudent to obtain other testing such as an MMA level.

Dr. Ulin:

We are also joined by Dr. Rahul Ganatra, who cared for the patient at the time the diagnosis was made. Dr. Ganatra, can you share the final diagnosis and provide an update on the patient?

Rahul Ganatra, MD, MPH, Director of Continuing Medical Education, VABHS:

The patient’s hemoglobin rose to 6.9 g/dL after transfusion of 2 units of packed red blood cells, and his dyspnea on exertion and fatigue improved. Iron studies, serum thiamine, serum folate, ADAMTS13 activity levels, and AM cortisol level were normal. Upon closer examination of the peripheral blood smear, rare hypersegmented neutrophils were noted. Serum B₁₂ level returned below assay (< 146 pg/mL), and serum MMA was 50,800 nmol/L, confirming the diagnosis of severe vitamin B₁₂ deficiency. Antibodies against intrinsic factor were detected, confirming the diagnosis of pernicious anemia. Treatment was initiated with intramuscular cyanocobalamin every other day and was transitioned to weekly dosing at the time of hospital discharge. After excluding adrenal insufficiency, his levothyroxine dose was increased. Finally, a liver mass biopsy confirmed a concomitant diagnosis of HCC. The patient was discharged home. Five weeks after discharge, his serum B₁₂ level rose to > 1000 pg/mL, and 10 months after discharge, his TSH fell to 0.97 uIU/mL. Several months later, he underwent stereotactic body radiotherapy for the HCC. One year after his initial presentation, he has not resumed work as a barber.