[Solitary spinal plasmacytoma].
The authors report 11 cases of solitary plasmocytoma of the spine. This tumour mainly affects men (9 cases) before the age of myeloma (average age 56 years). The back pain is associated with radicular irradiation (9 cases) and objective neurological signs (5 cases). The site was dorsal (5 cases), lumbar (5 cases) and rarely sacral (1 case). The vertebral lesion was either lysis (5 cases), a very characteristic polycystic appearance (5 cases) or common vertebral collapse (1 case). A lesion of the posterior arch was common (9 cases). A monoclonal immunoglobulin was demonstrated in the serum of 7 patients. Radiochemotherapy resulted in a reduction (2 cases) or complete regression (3 cases) of the monoclonal component. Radiotherapy alone did not prevent an increase of the monoclonal peak in 2 cases, nor the later occurrence of a monoclonal immunoglobulin in 2 other cases. An increase in polyclonal Ig. was an early sign of remission and their fall heralded myelomatous dissemination. The patients were followed up for an average of 6 years (range 1-16 years). The solitary course varied from 3 months to 16 years. Four patients developed metastatic plasmocytoma; 3 had medullary invasion after 1, 4, and 10 years.