Solitary bone and extramedullary plasmacytoma.

Less than 5% of patients with a plasma cell dyscrasia present with a single bone (SBP) or extramedullary plasmacytoma (EMP) without evidence of systemic disease (normocalcemia, absence of anemia, preservation of uninvolved immunoglobulins, or renal disease attributable to myeloma). Diagnosis requires biopsy confirmation of a monoclonal plasma cell infiltrate from a single site. The treatment of choice for both entities is radiotherapy given with curative intent (> 4000 cGy) resulting in long term disease-free survival in approximately 30% of patients with SBP and 65% of patients with EMP.