Objective: To determine the role of fine needle aspiration cytology in the diagnosis of extramedullary plasmacytoma.
Study design: The study group consisted of 13 patients with palpable masses at various sites. The tumors were aspirated for cytologic study.
Results: The smears revealed groups of mature and immature plasma cells at various stages of maturation. Mature plasma cells showed an eccentric nucleus and abundant, deep, basophilic cytoplasm with a paranuclear halo. Plasmablasts (immature plasma cells) showed a prominent, eccentric nucleus with single, large nucleolus and abundant, deep, basophilic cytoplasm with no paranuclear halo. Binucleate and multinucleate forms were also seen quite often. The tumors were excised, and the histologic sections confirmed the cytologic diagnosis. All the patients received radiotherapy. One patient (18 years old) developed recurrence and died due to extensive infiltration into the maxilla and mandible. Two patients (57 and 62 years) developed multiple myeloma one to two years after the excision of tumors, and both died two to three months later. The remaining 10 patients were alive and well at this writing.
Conclusion: The smears from all 13 patients were diagnosed as extramedullary plasmacytomas by fine needle aspiration cytology.