The diagnosis is made on a bone biopsy or aspirate from dominance of mature to partly atypical plasma cells, and constitutes 5% of the plasma cell neoplasias. Lytic solitary destruction of bone is usually evident by X-ray.
Some patients may have monoclonal gammopathy from serum protein electrophoresis.
The prognosis is relatively good, but over half of patients develop generalized disease (multiple myeloma).
Treatment consists of radiation therapy as 2 Gy x 20. For details of field modeling, see the chapter under radiation therapy. The distance from the macrotumor to the field borders follows the same principles as described under follicular lymphomas.
The goal of treatment is to cure the disease.