Systemic leishmaniasis mimicking malignant histiocytosis.

A 22-year-old man with fever, hepato-splenomegaly and severe pancytopenia is described in whom the histologic features of the spleen, liver and lymph nodes were consistent with malignant histiocytosis. Characteristic Leishman-Donovan bodies were demonstrated on a bone marrow aspirate, and the diagnosis of visceral leishmaniasis was confirmed by culturing the flagellated forms of the pathogen, and by an excellent response to sodium stibogluconate. In view of the similarity in clinical and histologic appearance, visceral leishmaniasis must be considered in the differential diagnosis of malignant histiocytosis in geographic areas where leishmaniasis is still endemic.