Plasma cell leukemia of IgG secreting type: A rare case

Abstract

Plasma cell leukemia is very rare comprising 2% plasma cell dyscrasias. We report a case of a 49-year-old male with complaints of chest pain, breathlessness, and acute attacks of gastroenteritis. On examination, there was marked pallor and hepatosplenomegaly. X-ray and computed tomography (CT) scan revealed multiple paratracheal lymph node enlargements. However, there was no diffuse osteopenia or multiple osteolytic lesions. Laboratory analysis revealed high serum calcium 11.5 mg/dL, low hemoglobin 5 g/dL, normal WBC count, thrombocytopenia 22000/mm³ and elevated erythrocyte sedimentation rate (ESR). Peripheral smear showed many atypical cells (41%) with blastoid morphology, giving a blood picture of acute leukemia. However, on closer inspection many of them appeared plasmacytoid. There was marked rouleaux formation of red cells in the background. Bone marrow aspirate and biopsy also revealed near total replacement by such atypical cells with plasmacytoid morphology. Serum electrophoresis revealed a prominent M spike and immunofixation revealed IgG heavy chain and kappa light chain immunostaining ruling out the possibility of Waldenström’s macroglobulinemia. Plasma cell leukemias are predominantly IgD and IgE secreting type. This case is rare in that it is IgG secreting type. Plasma cell leukemias are very aggressive and with higher incidence of organomegaly, lymphadenopathy, thrombocytopenia, hypercalcemia, renal impairment and surprisingly lesser occurrence of lytic bony lesions as in our case.