[A case of extramedullary plasmacytoma of the epipharynx--pathological diagnosis using multiple supplementary methods].

A rare case of extramedullary plasmacytoma of the epipharynx is reported. A 76-year-old woman presented with a one-year history of postnasal drip. Physical examination revealed a mass lesion in her epipharynx without cervical lymph node swelling. Biopsy of the mass showed diffuse proliferation of plasma cells at the light and electron microscopic levels. Immunohistochemical examination demonstrated monoclonal exhibition of IgA and kappa-light chain in the tumor cells. Furthermore, in flow cytometric analysis, the tumor cells were found to be CD10- CD19- CD20- CD22- HLA-DR- CD38++ sIg- EMA+, a typical phenotype of plasmacytoma. Additionally, rearranged bands were identified in Southern blot analysis of the tumor extract using probes for immunoglobulin heavy chain and kappa-light chain. Serum myeloma-protein and urine Bence-Jones protein were negative. Bone marrow examination, X-ray examination, CT scanning and 67Ga- and 99mTc-scintigrams showed no other systemic lesions. She received irradiation of 58 Gy to the epipharyngeal area over 7 weeks, followed by transnasal endoscopic resection using KTP/532 laser. The patient is free of disease six months after surgery, and is currently under close follow-up.