Solitary Plasmacytomas: Current Status in 2025

Solitary plasmacytoma refers to a neoplastic, clonal proliferation of plasma cells forming a single mass. They are divided based on their origin site; solitary bone plasmacytomas originate from the bones, and extramedullary plasmacytomas represent extraosseous tumors. These are rare tumors but carry a risk of transforming to multiple myeloma; thus, optimal management and meticulous follow-up are needed. Their rarity poses a major challenge in conducting large-scale clinical trials, leaving important gaps in evidence regarding best practices. Newer imaging techniques have improved the quality of staging, management decisions, and outcomes. Radiation still has a significant role in treatment algorithms, and adjuvant chemotherapy is gaining more importance; trials are underway in this area. Follow-up should contain biochemical tests as the proposed response definition criteria. We aimed to review the key studies and guidelines in this paper.