Malignant fibrous histiocytoma of the uterus.

A 56-year-old menopausal woman was admitted to hospital because of vaginal spotting of several months duration. The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy and omentectomy. On divalving, the uterus showed an ulcerated nodule 8 cm in diameter, protruding into the uterine cavity from the posterior wall. Histologically the tumor had a typical morphology of malignant fibrous histiocytoma (MFH). Multinucleated giant cells were strongly positive for CD 68 alpha antichymotripsin and alpha antitrypsin. Mononuclear cells also showed the same immunohistochemical pattern though less intensive than the giant cells. The cells were uniformly negative for S-100 protein, myoD1, myogenin desmin and actin. Electron microscopical investigation disclosed ultrastructural features compatible with the histiocytic nature of the tumor. Thirty-three months later the patient was free of disease.