Extrapulmonary small cell carcinoma of the liver: clinicopathological and immunohistochemical findings.

Patients with primary small cell carcinoma of the liver have rarely been described in medical literature. Knowledge of clinical, pathological and immunohistochemical properties remains limited. We described an 82-year-old female patient with primary small cell carcinoma of the liver. Histologically, the tumor showed typical morphology of a pulmonary small cell carcinoma. Immunohistochemically, the tumor revealed neuroendocrine differentiation; positive reaction for chromogranin, synaptophysin, CD56, and neuron specific enolase. The tumor was also positive for TTF-1 and c-kit but completely negative for hepatocyte, carcinoembryonic antigen, cytokeratin 7; 19; and 20. Herein, we discussed the clinical, pathological and immunohistochemical findings of extrapulmonary small cell carcinoma of the liver and reviewed the relevant literature.