Solitary extramedullary plasmacytoma

Abstract

A 70-year-old man presented with nasal airway obstruction due to a pedunculated pharyngeal mass. Histopathological examination confirmed the diagnosis of a solitary extramedullary plasmacytoma, with no evidence of multiple myeloma on diagnostic work-up. Plasma cell neoplasms typically manifest either as solitary plasmacytomas (5–10% of cases) or as multiple myeloma (90–95%). Solitary plasmacytomas, characterized by localized clonal proliferation of plasma cells without systemic involvement, most commonly arise within bone but may also occur in extramedullary sites. In these cases, symptoms are primarily related to the local mass effect. The standard treatment for solitary extramedullary plasmacytoma is complete surgical excision when feasible, or curative radiotherapy, which may also serve as complementary therapy in cases of incomplete resection. Compared with osseous plasmacytoma, the extramedullary variant generally has a more favorable prognosis. Following local therapy, only a minority of patients develop local recurrence, while 10–20% progress to multiple myeloma. The five-year overall survival rate ranges from 40% to 85%, highlighting the importance of close follow-up for at least five years. In our patient, given a radical surgical resection, no additional therapy was administered. Subsequent follow-up (currently nine years after diagnosis) has shown no evidence of local recurrence or progression to multiple myeloma.