Atypical blast morphology of primary plasma cell leukemia with renal involvement and plasmablasts in urine.

Primary plasma cell leukemia (PCL) is a rare and aggressive variant of plasma cell (PC) myeloma characterized by high levels of circulating PCs. Clinical presentation is like other acute leukemia, with extramedullary infiltration of various tissues and organs being a frequent complication. The disease has a fulminant course and poor prognosis. Morphology of PCs in PCL includes a spectrum of maturity, with most cases having lymphoplasmacytoid or plasmablastic morphology. Presentation as more primitive cells that do not resemble PCs is even rarer and requires additional morphological and immunophenotypic studies. We present a case of 79-year-old woman who presented with severe pancytopenia and lobar pneumonia. Laboratory and clinical evaluation revealed primary, nonsecretory PCL with atypical, immature blast morphology, extramedullary renal involvement, and plasmablasts in urine. Despite therapeutic efforts the patient succumbed to the disease. Detection of PCs in the urine indicates extramedullary spread of disease, especially without accompanying hematuria, and may contribute to impairment of renal function, what is already a frequent complication in these patients.