Multiple Solitary Plasmacytoma: A Rare Presentation

Plasmacytomas are localized tumors of monoclonal plasma cells, typically affecting the axial skeleton and present as solitary bone lesions known as solitary bone plasmacytomas (SBP). Another type of plasmacytomas are extramedullary plasmacytomas (EP) that are localized plasma cell neoplasms affecting the soft tissues such as skin, brain lymph nodes etc. These tumors are account for 5-10% of all plasma cell disorders and among these tumors a rare entity is a multiple solitary plasmacytoma (MSP). MSPs are rare and account for only 5% of all SBPs. MSP presents with multiple SBPs with or without EPs with no bone marrow involvement as multiple myeloma. Literature is limited on MSP as it is a rare diagnosis. Here, we present a case of a 64-year-old male who presented with shoulder pain after a fall, found to have an SBP of the right shoulder, SBP of left femur and a left hypopharyngeal EP. The tumors were excised and he was treated with 6 cycles of bortezomib and dexamethasone. After chemotherapy and radiation patient showed good response and remained in remission on follow up.