Chromosomal imbalances in primary hepatic carcinosarcoma.

Hepatic carcinosarcoma is an infrequent biphasic tumor composed of carcinomatous and sarcomatous elements, harboring an unfavorable prognosis. The developmental origin of both tumor components and possible molecular genetic mechanisms involved in tumorigenesis are still unclear. We report here a case of hepatic carcinosarcoma in a 76-year-old patient. The tumor was surgically resected and examined histopathologically including immunohistochemical staining. Focal hepatocellular differentiation was detected in the carcinomatous components but also in the pleomorphic undifferentiated spindle cells. Comparative genomic hybridization revealed amp 1q, -4q, -5p14pter, -5q13q31, +6p, -6q, -8p12pter, -12p, -13q12q14, -14q in the carcinomatous components, and +6p, -10q25qter, -22q in the sarcomatous components. The common +6p harbors the serum response factor gene encoding a transcription factor involved in cell proliferation, migration, and differentiation, confirmed by immunostaining. Hepatic carcinosarcoma is a tumor with biphasic morphology but possible monoclonal origin, showing advanced tumor progression in the carcinomatous areas.