Abstract
The clinical and pathological features, including ultrastructural and immunocytochemical findings, of 2 cases of primary malignant fibrous histiocytoma of the uterus are reported. One patient had pulmonary metastases at the time of hysterectomy: she developed pelvic recurrence and died 3 mth after operation. The other patient was well and apparently free of disease 6 mth after hysterectomy. Histologically both tumours resembled pleomorphic leiomyosarcoma, and the diagnosis of a malignant fibrous histiocytoma was confirmed only after electron microscopic and immunocytochemical studies. Hormone receptor assay for estrogen and progesterone was positive in both tumours. Anti-estrogen treatment was started in one case but was ineffective.