Extramedullary plasmacytoma of oral cavity: Series of three unusual cases at unusual locations

Abstract

Plasmacytoma is a monoclonal neoplastic proliferation of plasma cells of unknown etiology, presenting as a solitary discrete mass either in soft tissue as extramedullary plasmacytoma (EMP) or in bone as solitary bone plasmacytoma or as disseminated multiple myeloma (MM). EMP is a very rare manifestation, accounting for approximately 3% of all plasma cell neoplasms and <1% of all head and neck malignancies, with oral cavity being the rarest. We hereby report a series of three unusual cases of EMP, involving buccal mucosa, hard palate, and right retromolar trigone, rarely reported in literature, treated with definite radiotherapy after immunohistochemical studies confirmed the diagnosis. At present, patients are on regular follow-up without evidence of progression to MM. This series is presented with review of literature to highlight the extremely uncommon sites in head and neck where this disease entity can manifest, thus posing a diagnostic and therapeutic dilemma for treating physicians.