Extramedullary plasmacytoma is a monoclonal proliferation of plasma cells without bone destruction or intramedullary involvement, being characterized by only soft tissue involvement. Extramedullary plasmacytomas do not present with symptoms of multiple myeloma, but with a mass and accompanying symptoms.
The patient reported herein was a 49-year-old woman who presented to our hospital with the chief complaint of discomfort while swallowing. She was identified as having a mass (maximum diameter 27 mm) in the posterior wall of the nasopharynx. There was no evidence of extension into surrounding tissues or bone destruction. Therefore, surgery was selected as the initial treatment. There are two possible approaches to the nasopharynx: a transnasal approach under endoscopic guidance and a transoral approach. In this case, the base of the tumor was determined as being caudal to the extension of the hard palate, and transoral videolaryngoscopic surgery (TOVS) was performed as the procedure of choice. Because of the positive deep margins, the patient also received postoperative radiation therapy. No recurrence or metastasis has been observed until now, 3 years since the surgery. It is reported that extramedullary plasmacytoma show transformation into multiple myeloma in 17%–33% of patients; therefore, continued and careful follow-up after local treatment is necessary for early detection of transformation to multiple myeloma.
