Extramedullary Plasmacytoma of Base of Tongue: A Systematic Review.

OBJECTIVE: Identifying extramedullary plasmacytoma originating from the base-of-tongue, in order to evaluate its prevalence, characteristics, management, and treatment within the broader spectrum of head and neck extramedullary plasmacytoma. DATA SOURCES: A systematic review was conducted in PubMed, Web of Science, and Cochrane Library for publications up to August 2025. METHODS: Eligible studies were in English, verified by two reviewers independently. Articles were excluded if they lacked a diagnosis of extramedullary plasmacytoma, and localization to the base-of-tongue. RESULTS: Twenty-five studies (case reports and case series) comprising of 30 individual cases were identified. The mean age was 63.6 years, with a male-to-female ratio of 5.25:1. Common symptoms included odynophagia, dysphagia, and sore throat. Tumors were confined to the base of tongue in 44% of cases, with others involving cervical lymph nodes or adjacent sites. All specimens showed plasma cell histology; bone marrow, Bence-Jones, and skeletal surveys were negative. Imaging (CT, PET-CT, MRI) revealed additional sites in a minority. Radiotherapy was the main treatment (23 patients, mean dose 45 Gy), often combined with surgery or chemotherapy. Mean follow‑up was 47.7 months, with generally favorable survival, though four cases had recurrence or partial control. CONCLUSIONS: In this review, 30 cases were identified, all meeting accepted diagnostic criteria for extramedullary plasmacytoma with exclusion of other plasma cell disorders. Radiotherapy was the most frequent treatment modality with survival among described cases as generally favorable. Extramedullary plasmacytoma should be included in the differential diagnosis of lesions arising in the base of tongue.