MM-326: Visceral Leishmaniasis Mimicking Multiple Myeloma

Abstract

Context Western parts of the Republic of North Macedonia are considered endemic regions for leishmaniasis. Due to the broad spectrum of hematologic manifestations of visceral leishmaniasis (VL), this anthropozoonosis may be occasionally misdiagnosed as a hematological disease. Objective We present here a patient with VL whose initial clinical and laboratory findings mimicked multiple myeloma and led us to series of diagnostic procedures for plasma cell dyscrasia. Patient Case Report A 66-year-old woman presented at our institution with a history of back pain radiating down the legs. Physical examination revealed massive splenomegaly crossing the abdominal midline. Laboratory data showed pancytopenia (Hb 91 g/L; WBC 1.8 x 109/L; PLT 26 x 109/L), and the peripheral blood smear did not show any specific findings. What led us to suspect multiple myeloma was hyperproteinemia (96 g/L) due to hypergammaglobulinemia with IgG monoclonal components (IgG 71.5 g/L). Bone marrow biopsy with bone marrow aspiration was performed, and clusters of atypical plasma cells up to 20% infiltration were noted, further confirming the initial diagnosis. Still, we noted on M-Grunwald-Giemsa-stained bone marrow aspirate smears intra- and extracellular inclusions, resembling leishmaniasis. Additionally, PCR for B-cell gene rearrangement was negative. The diagnosis of VL was reached by a positive leishmania immunofluorescence antibody test. The patient was treated with amphotericin for 10 days with protracted resolution of the symptoms. The complete recovery of the blood counts was noted within three months. Still, monoclonal IgG, although decreased, remained high at the time of last visit (IgG 55 g/L), which is within three months of treatment. Conclusions Although endemic in our country, VL is rarely included in the differential diagnosis for clinicians, especially in cases with atypical clinical presentation. This case underlies the need for hematologists to consider this condition in patients presenting with uncertain yet common hematological abnormalities.