Malignant fibrous histiocytoma arising in a benign cystic teratoma of the ovary

Abstract

A rare case of malignant fibrous histiocytoma arising in a benign cystic teratoma of the right ovary is reported in a 42-year-old nulliparous married woman. Two-thirds of the tumor was occupied by a benign cystic teratoma, from which the remaining solid tumor was arising. The solid tumor was composed of both fibrous and histiocytic elements, showing diverse histologic findings: a storiform pattern of the fibrous elements, admixture of histiocytes and multinucleated giant cells, clumps of foam cells, and a patchy infiltrate of lymphocytes. The malignancy of the present tumor was established by assessing the bizarre neoplastic giant cells in the sarcomatous areas and also by the metastatic recurrence. This appears to be the first reported case of a malignant fibrous histiocytoma arising in a benign cystic teratoma.