Solitary bone plasmocytoma: Treatment and outcome features

Purpose. - To describe natural history of solitary bone plasmocytomas (SBO) after treatment. Patients and methods. - Between 1975 and 1998, we retrospectively identified 13 patients with SBO treated in the department of radiotherapy at Salah-Azaïz institute of Tunis. To be included in this study, three criteria were needed: histologic confirmation and only one bone lesion without medullary infiltration (or less than 10%). Mean age was 43 years (22-64) with sex-ratio of 3,3. Tumor sites were vertebra (6), flat bones (6) and tibia (1). Megavoltage radiotherapy was given to all patients, associated to surgery in eight cases (5 excisions and 3 laminectomies) and to chemotherapy in three. Results. - With a mean follow-up of 63 months, two local failures were noted at 24 and 48 months. Two patients developed multifocal lesions and one patient had an extramedullary lesion. Multiple myeloma occured in four patients (30%) after a median follow-up 3,5 years. Unfavorable outcome could not be predicted by age, gender or site of disease but by myeloma protein. Conclusion. - Radiotherapy is an effective local treatment for solitary bone plasmocytoma. Prospective studies are needed to better define predictive parameters of unfavourable outcome and indications of combined chemotherapy. © 2003 Elsevier SAS. Tous droits réserv́s.