Solitary Plasmacytoma Management and Outcomes

Abstract

Solitary plasmacytoma (SP) is a rare malignant tumour characterised by a localised collection of neoplastic plasma cells. SP is closely related to multiple myeloma (MM) which, in contrast, is characterised by widespread plasma cell neoplasia with systemic features including hypercalcaemia, bone disease, anaemia and/or renal impairment. SPs can manifest as a solitary bone plasmacytoma (SBP) or less commonly as a soft tissue mass i.e. solitary extramedullary plasmacytoma (SEP). SP is far less common than MM (~5% of plasma cell malignancies) and therefore there is a lack of high-quality data guiding management1. Like MM, SP is more common in males but has a lower median age of onset. SBP most commonly affects the axial skeleton 1,2, particularly the vertebrae, with SBP accounting for ~30% of malignant spinal bone tumours1. Less common sites of SBP include the ribs, clavicle and scapulae2. SEP (ratio approximately 10:1) are much less common than SBP1,3 and are most frequently seen in the upper respiratory tract and less commonly in the lower respiratory tract, gastrointestinal tract and rarely in sites such as breast and pituitary gland3. Five year overall survival(OS) following a diagnosis of SP is variable with reported ranges of 40-85%4.