Uncommon Presentation of Solitary Plasmacytoma in the Nasal Cavity: Diagnostic and Therapeutic Challenges.

Extramedullary solitary plasmacytoma (SP) is an uncommon tumor and is even rare in the head and neck locations. Here, we report the case of an 82-year-old man admitted to our department for the management of nasal cavity SP. Radiological investigation showed a locally advanced tumor making the patient a non-candidate for surgery. The patient had undergone radiotherapy alone to a total dose of 50 Gy, with 2 Gy per fraction five days a week. After a follow-up of nine months, the tumor recurred, and the patient was managed in the internal medicine department. He received palliative chemotherapy with the cyclophosphamide, dexamethasone, and thalidomide protocol which resulted in a good response. This case illustrates the diagnostic challenges and treatment complexities of SP, particularly in rare locations such as the nasal cavity.