Malignant histiocytic tumour presenting as a primary uterine neoplasms: a cytochemical and electron microscopy study.

A 41-year-old woman was admitted because of uterine bleeding. The diagnosis of malignant histiocytic tumor was suspected from microscopic examination of the material obtained with diagnostic curettage. Total hysterectomy was performed a week later and a complete pathological examination of the specimens was performed. Cytochemical and immunoperoxidase stains and electron microscopy confirmed that the neoplastic cells were derived from histiocytic elements, i.e. from the mononuclear phagocyte system.