- A collection of monoclonal plasma cells
- Can occur as isolated bone lesions (typically axial skeleton) or extramedullary (typically head/neck area, in particular nasopharynx and nasal cavity)
- Can occur concurrent w/Multiple Myeloma (in which case CRAB features present) or separately
- Development of palpable mass(es)
- Pain (e.g. boney, pathologic fx) or organ dysfunction based on location of plasmacytoma
- Fatigue, sob, pain if occur in conjunction w/myeloma
- Masses tend to be hard
- Can be multiple, boney or in soft tissue
- Diagnosed via biopsy of mass
- SPEP, plasma free light chains, skeletal survey, and bone marrow--> to exclude myeloma