Sarcomatous variant of malignant histiocytosis; a case report and review of the literature.

The case is that of a 21-year-old female with mediastinal and subcutaneous, tumors composed of sarcomatous growth of poorly differentiated histiocytes defined by enzyme histochemical staining, ultrastructural observation and detection of surface markers. At autopsy neoplastic cells in the solid tumor became less cohesive and pleomorphic with erythrophagia, while features in the lymph node draining from the tumor was compatible with the criteria of malignant histiocytosis. The place where such a sarcomatous variant of malignant histiocytosis should be placed within other histiocytic tumors is discussed and the literature reviewed.