Extramedullary plasmacytoma in the carotid space: Expanding the differential diagnosis

Abstract Plasma cell neoplasms have been classified into various types, with a range of clinical and radiological presentations. Extramedullary plasmacytoma (EMP) is a subset of plasma cell neoplasms which presents as an isolated non-osseous soft tissue mass. Though carotid space neoplasms are commonly encountered, EMP in the carotid space is rare and seldom considered in the initial differential diagnosis of a carotid space mass. These tumors can be treated by surgery or radiotherapy. On the other hand, the commonly encountered tumors in the carotid space are treated surgically. Also, it is mandatory to exclude multiple myeloma in the patients presenting with EMP. Hence, accurate and early diagnosis has therapeutic and prognostic implications. We report a rare case of EMP of the carotid space, describing the imaging features and the differential diagnoses with clues pointing to this rare entity.