Malignant histiocytosis. A clinical and morphological study of four cases.

Four patients with malignant histiocytosis are described. Major clinical signs were fever, lymphadenopathy, hepatomegaly and splenomegaly. Laboratory studies showed leukopenia, thrombocytopenia, low leukocyte alkaline phosphatase (LAP) score, normal erythrocyte sedimentation rate (ESR) and elevated serum triglycerides. There was evidence of bone marrow involvement in all four cases. Typical changes were seen in the histological study.