Rapidly Progressing Plasma Cell Leukemia with Underlying Plasmablastic Morphology: A Rare Case Report of a 25-Year Old Male

Multiple myeloma constitutes a wide spectrum of diseases ranging from slow-growing monoclonal gammopathy of undetermined significance to rapidly progressing plasma cell leukemia. It is a very rarely diagnosed hematological malignancy in those less than 30 years. A 25-year-old male presented with complaints of fatigue, and low-grade fever. On investigations, he was found to have bicytopeina and features of tumor lysis syndrome. This was initially thought to be consistent with a diagnosis of acute leukemia. Upon further analysis with bone marrow biopsy, serum protein electrophoresis, and immunofixation, the rare diagnosis of IgG myeloma with plasmablastic morphology was confirmed. However, it rapidly progressed and peripheral smear started showing clusters of plasma cells. Despite aggressive treatment, the patient succumbed to aggressive plasma cell leukemia with an underlying plasmablastic morphology. This case highlights the possibility of myeloma as one of the differentials in young patients especially the rare plasmablastic variant that can get misdiagnosed as acute leukemia. This aggressive morphology may also show rapid progression to plasma cell leukemia and has an adverse prognosis.