VISCERAL LEISHMANIASIS WITH A VERY-LOW DEGREE OF BONE-MARROW PARASITEMIA, MIMICKING MALIGNANT HISTIOCYTOSIS

Visceral leishmaniasis (VL) is common in the Middle East, the Mediterr anean region, East Africa and India. It is extremely rare in the west. Its manifestations can be protean with occasional cases presenting wi th 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 chemo therapy. The patient was an adult severely ill Sudanese who presented with a few months history of fever, cough, wasting, progressive spleno megaly, jaundice, pancytopenia and frank features of disseminated intr avascular coagulopathy. Bone marrow examination revealed extensive inf iltration by atypical hemophagocytosing histiocytes, consistent with m alignant histiocytosis. The routine search for amastigotes of Leishman ia was negative. An unexpected later positive serology for VL prompted us to search the bone marrow for Leishman-Donovan bodies. After ten h ours of expert search we identified three conclusive parasites, the fi rst one being detected after five hours of an intensive and compulsive microscopy. Diagnosis of VL was made and the patient was cured on ant i-protozoal medications. We conclude that in endemic regions for paras itic disorders, unusual presentations of common protozoal problems are more common than rare malignant disorders. In leishmania endemic area s of the world, one should utilize all the possible diagnostic resourc es, 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 f ew 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.