[Large cell neuroendocrine carcinoma of the lung; report of a case]

Large cell neuroendocrine carcinoma (LCNEC) is a rare type of lung cancer and it has the least favorable prognosis. We describe our experience with a patient in whom LCNEC was diagnosed. A 65-year-old man who was pointed out abnormal shadow on a chest X-ray film in the health screening was admitted to the hospital. Chest X-ray film and computed tomography (CT) scan showed a 4 x 3 cm mass in the left-S2. Poorly differentiated adenocarcinoma of the left lung was suspected based on CT guided cytology. An upper lobectomy of the left lung and dessection of the mediastinal lymph nodes were performed. This tumor showed light microscopic and immunohistochemical evidences of neuroendocrine differentiation. Further it showed positive responses in neuronspecific enolase (NSE), synaptophysin, and chromogranin-A stainings. Pathological diagnosis was stage IB (pT2N0M0) LCNEC. There have been no findings of tumor recurrence 22 months after the operation.