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Background
Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare, aggressive lung cancer subtype, comprising ~3% of lung malignancies. It commonly affects older, heavy smokers and presents at an advanced stage. Prognosis is poor, with a 5-year survival rate of 15–25% in metastatic disease.
Case Presentation
A 33-year-old previously healthy male presented with a month of abdominal and lower back pain, along with significant weight loss. Lab tests revealed elevated lipase (378), and he was initially treated for acute pancreatitis. Imaging revealed a 1.9 cm pancreatic head mass and three hypodense hepatic lesions. MRI confirmed these findings but remained inconclusive. An incidental 8 mm right lower lobe pulmonary nodule led to chest CT, identifying a dominant left lower lobe mass and mediastinal lymphadenopathy, raising suspicion for primary lung malignancy. The patient was discharged but returned three days later with worsening symptoms and a lipase of 754. Endoscopic biopsy of the pancreatic mass was deferred due to ongoing pancreatitis. A liver biopsy revealed neuroendocrine differentiation, positive for CK AE1/AE3, CK7, CK19, and synaptophysin. Molecular profiling showed PD-L1 (TPS 50%), low tumor mutational burden, microsatellite stability, and high loss of heterozygosity. Bronchoscopy revealed a left hilar mass, and lymph node biopsy confirmed LCNEC (CK7+, chromogranin+, TTF- 1+, synaptophysin+), establishing a diagnosis of stage IV pulmonary LCNEC with pancreatic and liver metastases. The patient began treatment with bevacizumab, paclitaxel, carboplatin, and atezolizumab, resulting in improvement in hilar, hepatic, and pancreatic lesions on further imagings. The patient was continued on chemoimmunotherapy.
Discussion
This case highlights an uncommon presentation of LCNEC in a young, non-smoking male, initially manifesting as pancreatitis due to pancreatic metastasis. The absence of pulmonary symptoms complicated the diagnosis. Histopathology and immunohistochemistry were essential. While no standardized treatment exists for LCNEC, platinum-based chemotherapy with immunotherapy remains the mainstay. PD-L1 expression may guide immunotherapy decisions.
Conclusions
Pulmonary LCNEC should be considered in metastatic neuroendocrine tumors, even in young, non-smoking patients without pulmonary symptoms. Early tissue diagnosis and molecular profiling are key to guiding management.
Background
Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare, aggressive lung cancer subtype, comprising ~3% of lung malignancies. It commonly affects older, heavy smokers and presents at an advanced stage. Prognosis is poor, with a 5-year survival rate of 15–25% in metastatic disease.
Case Presentation
A 33-year-old previously healthy male presented with a month of abdominal and lower back pain, along with significant weight loss. Lab tests revealed elevated lipase (378), and he was initially treated for acute pancreatitis. Imaging revealed a 1.9 cm pancreatic head mass and three hypodense hepatic lesions. MRI confirmed these findings but remained inconclusive. An incidental 8 mm right lower lobe pulmonary nodule led to chest CT, identifying a dominant left lower lobe mass and mediastinal lymphadenopathy, raising suspicion for primary lung malignancy. The patient was discharged but returned three days later with worsening symptoms and a lipase of 754. Endoscopic biopsy of the pancreatic mass was deferred due to ongoing pancreatitis. A liver biopsy revealed neuroendocrine differentiation, positive for CK AE1/AE3, CK7, CK19, and synaptophysin. Molecular profiling showed PD-L1 (TPS 50%), low tumor mutational burden, microsatellite stability, and high loss of heterozygosity. Bronchoscopy revealed a left hilar mass, and lymph node biopsy confirmed LCNEC (CK7+, chromogranin+, TTF- 1+, synaptophysin+), establishing a diagnosis of stage IV pulmonary LCNEC with pancreatic and liver metastases. The patient began treatment with bevacizumab, paclitaxel, carboplatin, and atezolizumab, resulting in improvement in hilar, hepatic, and pancreatic lesions on further imagings. The patient was continued on chemoimmunotherapy.
Discussion
This case highlights an uncommon presentation of LCNEC in a young, non-smoking male, initially manifesting as pancreatitis due to pancreatic metastasis. The absence of pulmonary symptoms complicated the diagnosis. Histopathology and immunohistochemistry were essential. While no standardized treatment exists for LCNEC, platinum-based chemotherapy with immunotherapy remains the mainstay. PD-L1 expression may guide immunotherapy decisions.
Conclusions
Pulmonary LCNEC should be considered in metastatic neuroendocrine tumors, even in young, non-smoking patients without pulmonary symptoms. Early tissue diagnosis and molecular profiling are key to guiding management.
Background
Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare, aggressive lung cancer subtype, comprising ~3% of lung malignancies. It commonly affects older, heavy smokers and presents at an advanced stage. Prognosis is poor, with a 5-year survival rate of 15–25% in metastatic disease.
Case Presentation
A 33-year-old previously healthy male presented with a month of abdominal and lower back pain, along with significant weight loss. Lab tests revealed elevated lipase (378), and he was initially treated for acute pancreatitis. Imaging revealed a 1.9 cm pancreatic head mass and three hypodense hepatic lesions. MRI confirmed these findings but remained inconclusive. An incidental 8 mm right lower lobe pulmonary nodule led to chest CT, identifying a dominant left lower lobe mass and mediastinal lymphadenopathy, raising suspicion for primary lung malignancy. The patient was discharged but returned three days later with worsening symptoms and a lipase of 754. Endoscopic biopsy of the pancreatic mass was deferred due to ongoing pancreatitis. A liver biopsy revealed neuroendocrine differentiation, positive for CK AE1/AE3, CK7, CK19, and synaptophysin. Molecular profiling showed PD-L1 (TPS 50%), low tumor mutational burden, microsatellite stability, and high loss of heterozygosity. Bronchoscopy revealed a left hilar mass, and lymph node biopsy confirmed LCNEC (CK7+, chromogranin+, TTF- 1+, synaptophysin+), establishing a diagnosis of stage IV pulmonary LCNEC with pancreatic and liver metastases. The patient began treatment with bevacizumab, paclitaxel, carboplatin, and atezolizumab, resulting in improvement in hilar, hepatic, and pancreatic lesions on further imagings. The patient was continued on chemoimmunotherapy.
Discussion
This case highlights an uncommon presentation of LCNEC in a young, non-smoking male, initially manifesting as pancreatitis due to pancreatic metastasis. The absence of pulmonary symptoms complicated the diagnosis. Histopathology and immunohistochemistry were essential. While no standardized treatment exists for LCNEC, platinum-based chemotherapy with immunotherapy remains the mainstay. PD-L1 expression may guide immunotherapy decisions.
Conclusions
Pulmonary LCNEC should be considered in metastatic neuroendocrine tumors, even in young, non-smoking patients without pulmonary symptoms. Early tissue diagnosis and molecular profiling are key to guiding management.