Multifocal Colonic Masses as a Presentation of Secondary Extramedullary Plasmacytoma in Relapsing-Refractory Multiple Myeloma: A Case Report and Review of Literature

BACKGROUND: Multiple myeloma (MM) is a common plasma cell malignancy; however, extramedullary multiple myeloma (EMM) is an aggressive phenotype in which malignant plasma cells proliferate outside of the bone marrow. AIMS: Extramedullary plasmacytomas (EMP) are uncommon and gastrointestinal involvement is exceedingly rare. CASE PRESENTATION: Here, we present a case of multifocal secondary colonic EMP in a patient with relapsed refractory multiple myeloma (RRMM) and review literature demonstrating other cases of secondary colonic EMP.