Extrapulmonary small-cell carcinoma of the liver.

A 53-year-old man was admitted to our hospital for the evaluation of a mass (13 x 10 cm) in the left lobe of the liver seen by imaging studies. On subsequent biopsy of the mass, the lesion was histologically diagnosed as malignant small round-cell tumor, consistent with metastatic small-cell carcinoma. Segment IV segmentectomy was performed. On pathological examination, the mass showed a yellowish-gray granular appearance with multifocal hemorrhage and necrosis. The phenotypes shown by immunohistochemistry revealed characteristic patterns of small-cell carcinoma (neuron-specific enolase [NSE]+, synaptophysin+, c-Kit+, cluster designation [CD]56+, epithelial membrane antigen [EMA]+, cytokeratin [CK]7-). High resolution-computed tomography (HRCT) revealed inactive pulmonary tuberculosis with small calcified tuberculoma in the right upper lobe. Sputum cytology was negative for malignancy. The postoperative course was uneventful, and platinum-based chemotherapy (cisplatin, etoposide) was initiated.