[Malignant histiocytosis. Histiocytic medullary reticulosis]

The Authors report a case of malignant histiocytosis apparently localized only in the spleen. The diagnosis of the disease, characterized at the onset by moderate leukopenia and thrombocytopenia, was made possible by the histopathologic examination of the spleen following splenectomy. The disease shows a chronic course. The Authors discuss the clinical and histological features of the case.