Cytodiagnosis of extramedullary plasmacytomas

Extramedullary plasmacytoma (EMP) constitutes approximately 4% of all plasma cell neoplasms. It may present as the sole manifestation of plasma cell neoplasm, as a solitary plasmacytoma of the bone or as a consequence of multiple myeloma. This study was done to determine the role of fine needle aspiration cytology (FNAC) in the diagnosis of EMP.

In our study 8 cases of EMP at various sites were diagnosed on FNAC. In 3 patients EMP was the initial presentation of plasma cell neoplasm. In the remaining 5 patients the tumors occurred during the course of treatment for multiple myeloma.

The lesions were located at various anatomic sites, including lymph node, scalp, breast, jaw, rib, clavicle and soft tissue swelling in the retrosternal region. The smears prepared from the aspirates in all cases revealed numerous plasma cells at various stages of maturation, leading to a diagnosis of EMP. Radiologic and bone marrow findings also substantiated the diagnosis of multiple myeloma in all but 1 case.

FNAC offers a rapid, reliable and accurate diagnosis of EMP and thus allows initiation of appropriate treatment.