Abstract
Visceral leishmaniasis (VL) is common in the Middle East, the Mediterranean region, East Africa and India. It is extremely rare in the west. Its manifestations can be protean with occasional cases presenting with features indistinguishable on clinical or even histological grounds from malignant disorders. We report here a unique case of VL who was diagnosed as malignant histiocytosis (MH) and planned to receive chemotherapy. The patient was an adult severely ill Sudanese who presented with a few months history of fever, cough, wasting, progressive splenomegaly, jaundice, pancytopenia and frank features of disseminated intravascular coagulopathy. Bone marrow examination revealed extensive infiltration by atypical hemophagocytosing histiocytes, consistent with malignant histiocytosis. The routine search for amastigotes of Leishmania was negative. An unexpected later positive serology for VL prompted us to search the bone marrow for Leishman-Donovan bodies. After ten hours of expert search we identified three conclusive parasites, the first one being detected after five hours of an intensive and compulsive microscopy. Diagnosis of VL was made and the patient was cured on anti-protozoal medications. We conclude that in endemic regions for parasitic disorders, unusual presentations of common protozoal problems are more common than rare malignant disorders. In leishmania endemic areas of the world, one should utilize all the possible diagnostic resources, and possibly stretch the routine search to its fullest, to confirm the diagnosis of VL and exclude MH. Perhaps this is one of the very few clinical situations in which histological diagnosis of a malignancy can be erroneous. VL should be excluded in every case of MH diagnosed in the geographical area of leishmaniasis.