Extramedullary plasmacytoma diagnosed by fine needle aspiration cytology. A report of four cases

Fine needle aspiration cytology (FNAC) diagnosis of plasmacytoma is rare.

Four cases of plasmacytoma were diagnosed by FNAC. The patients had clinically palpable lesions in more than one anatomic site. The sites of aspiration included lymph nodes, soft tissue swellings and a bony mass. The ages of the patients ranged from 42 to 80 years (mean, 62 years), and all the patients were male. All four cases showed a monomorphous population of well-differentiated myeloma cells in aspiration smears. Serum electrophoresis demonstrated an M spike in all cases, and Bence Jones protein was detected in the urine sample in one case. Radiologic and bone marrow findings also substantiated the diagnosis of multiple myeloma.

FNAC diagnosis of plasmacytoma at extramedullary sites offers the opportunity for noninvasive verification of widespread involvement.