Primary carcinosarcoma of the liver: clinicopathologic features of 5 cases and a review of the literature.

Carcinosarcoma of the liver is very rare worldwide. The terminology and pathogenesis of hepatic carcinosarcoma remain controversial issues. In this article, we studied the clinicopathologic features of 5 cases of hepatic carcinosarcomas (matching the World Health Organization definition), analyzed the clinical data, histologic and immunohistochemical (IHC) results, and discussed the terminology, pathologic differential diagnoses, pathogenesis, and prognosis. The patients were 40 to 68 years old, and included 4 males and 1 female. All patients were Hepatitis B surface antigen positive with para-tumorous cirrhosis. The largest dimensions of the neoplasms ranged from 6.0 to 14.0 cm. Satellite nodules, portal vein tumor thrombi, direct invasion into local tissues (right diaphragm, right adrenal gland, and gastric wall) as well as metastatic foci in lungs and abdominal lymph nodes were identified. Pathologically, the neoplasms consisted of carcinomatous and sarcomatous components. The carcinomatous components were exclusively conventional hepatocellular carcinomas in all 5 cases, whereas the sarcomatous components exhibited complex features. Confirmed by IHC studies, the sarcomatous elements in different cases included rhabdomyosarcomas, malignant fibrous histiocytomas, fibrosarcoma, and poorly differentiated spindle cells without distinctive differentiation. Furthermore, the sarcomatous elements in these 5 neoplasms stained negative for all the epithelial markers we applied for IHC staining, which support the pathologic diagnosis of carcinosarcoma rather than sarcomatoid carcinoma. The presence of transitional zones between carcinomatous and sarcomatous components may support the transformation theory. Four patients with palliative hepatectomy died within 6 months, whereas 1 patient is still alive 21 months after radical resection. The poor prognosis of hepatic carcinosarcoma may be due to their highly invasive and metastatic features. Radical resection of early stage hepatic carcinosarcoma may contribute to a relatively optimistic prognosis.