Fine needle aspiration cytology in extramedullary plasmacytoma

OBJECTIVE: Extramedullary plasmacytoma is a rare plasma cell neoplasm. It can occur as the sole manifestation of plasma cell neoplasm, as a metastasis from another extramedullary plasmacytoma, as a solitary plasmacytoma of the bone or as a consequence of multiple myeloma. These plasma cell tumors can occur anywhere and have to be differentiated from other neoplasms, infectious processes and chloroma. STUDY DESIGN: We report the findings of fine needle aspiration cytology (FNAC) in 18 patients with extramedullary plasmacytoma. In six patients extramedullary plasmacytoma was the initial presentation of plasma cell neoplasm. In the remaining 12 patients the tumors occurred under or after treatment of plasma cell disease. RESULTS: Eleven lesions were located in the skin, seven in the lymph nodes, one in the liver and another in the spleen. Two patients with known diagnoses of plasma cell disease were thought, before FNAC, to have an infection, and two had a histologic diagnosis of non-Hodgkin's lymphoma. In 13 of 18 patients, cytologic smears showed anaplastic plasma cells. CONCLUSION: FNAC is a front-line investigative procedure in diagnosing extramedullary plasmacytoma.