Objective: The authors analyzed the clinical characteristics and treatment methods of patients with extramedullary plasmacytoma treated by the same treatment team at a single institution for 24 years and identified factors affecting the prognosis of patients.

Methods: The study enrolled 10 patients with a final diagnosis of extramedullary plasmacytoma of the head and neck region in a single institution from January 2001 to December 2024.

Results: Of the 10 patients with extramedullary plasmacytoma (57.9±21.9 y, 8 male), 7 had tumors in the nasal cavity and 1 each in the tonsil, larynx, and hard palate. The mean tumor size was 3.4±2.7 cm (range, 1.4-9.0 cm). According to the staging system, 7 patients had stage 1 tumor, 3 had stage 3, and none had stage 2. Combination treatment with radiotherapy and surgery was the most common (70%). The mean dose of radiotherapy was 46.7±5.5 Gy. The 5-year relapse-free survival rate and 5-year survival rate of extramedullary plasmacytoma of the head and neck regions were 60% and 80%. The only statistically significant finding was that higher-stage extramedullary plasmacytoma was associated with worse overall survival.

Conclusions: The authors recommend the combination of radiotherapy and surgery for extramedullary plasmacytoma of the head and neck region when there are no major cosmetic or functional concerns associated with surgery.