Extramedullary plasmacytomas and solitary plasma cell tumours of bone

We describe clinical features and treatment results in 25 patients with solitary osseous (SOP) and 18 patients with solitary extramedullary plasmacytoma (EMP). 41 patients were treated with high-voltage radiotherapy, median 40 Gy in 20 fractions. Surgery was part of the treatment in 21 and chemotherapy in 5 patients. The median age in both groups was 56 years, with a preponderance of males. Myelomatosis developed in 10 SOP and 2 EMP patients, and this development did not correlate with the presence or absence of an M-component at the time of diagnosis of plasmacytoma. The estimated 5- and 10-y survival was 87% and 76% without a statistical difference between SOP and EMP groups. The patients in the SOP group usually died from myelomatosis while EMP patients died from other causes.