[A case of primary small cell carcinoma of the liver]

Primary small cell carcinoma of the liver is an extremely rare tumor. Extrapulmonary small cell carcinoma shares many features of pulmonary small cell carcinoma, including the histological appearance, the aggressive clinical behavior and the frequent short-lasting response to either chemotherapy or radiotherapy. We experienced a 56-year-old man with small cell carcinoma that arose in the liver. Abdominal CT scan showed an 8 cm size, low density mass in the segment 4 of the liver and also multiple lymphadenopathies. Chest X-ray showed no abnormal finding, but the chest CT showed a right lower paratracheal lymphadenopathy. The pathological findings showed nests of small round cells with fine granular chromatin, inconspicuous nucleoli and scanty cytoplasm. Distinct and strong immunoreactions were seen for CD56 and c-kit, and sparse immunoreaction was seen for synaptophysin. Thyroid transcription factor-1 showed no immunoreaction. The tumor did not decrease in size despite chemotherapy. We report this case along with a review of the relevant literatures.