Malignant fibrous histiocytoma arising in the liver.

A unique type of hepatic sarcoma in an adult was composed of pleomorphic fibrohistiocytic cells with benign cystic structures. The malignant mesenchymal component was morphologically similar to malignant fibrous histiocytoma of the soft tissue. The cystic epithelial structures appeared to be formed by the cystic transformation of the entrapped bile ducts and ductules. Malignant fibrous histiocytoma can arise in the liver, but the original architecture of the liver may affect or modify the histologic characteristics of the sarcoma.