OBJECTIVETo study the clinical characteristics and the prognosis of solitary bone plasmacytoma (SBP).

METHODSFrom June 1997 to June 2002, ten SBP patients were treated in our department. Two lesions were in sacrum, two in pelvis, the other six lesions were in proximal femur, femoral diaphyseal, scapula, thoracic vertebra, proximal humus, and rib respectively. The preoperative laboratory tests were normal. Operation was performed on all patients. The pathologic diagnose was plasmacytoma and then they underwent further laboratory examination, urine Bence-Jone protein is positive in 3 patients, serous IgG value was higher than normal in 2 patients, abnormal M protein was found in electrophoresis in 2 patients. All patients received radiotherapy postoperatively.

RESULTSFour patients were excluded, whose follow-up were lessen than ten months, the other six patients's average follow-up is 28.2 months (from 18 to 48 months), one patient who developed multiple myeloma (MM) six months postoperatively received chemotherapy using M2 protocol and died 21 months after operation. The other five patients had disease-free survive and remain solitary bone lesion after the treatment of surgery and radiology.

CONCLUSIONCompared with MM, SBP patients are younger, the therapeutic results and prognosis are better. The main prognostic factors include age, the size of lesion, the axial bone lesion, persistence of myeloma protein after radiotherapy, early diagnosis and treatment, and so on.