Summary of patient characteristics and treatment outcomes
| Solitary plasmacytoma patients, n | 34 |
| Median age, years (range) | 65 (32–83) |
| Male, n (%) | 23 (68) |
| Site | |
| Solitary bone plasmacytoma, n (%) | 27 (79) |
| Thoracic vertebrae | 11 (41) |
| Lumbar vertebrae | 7 (26) |
| Cervical vertebrae | 2 (7) |
| Long bones | 2 (7) |
| Other | 5 (19) |
| Solitary extramedullary plasmacytoma, n (%) | 7 (21) |
| Skin / soft tissue apart from head and neck | 3 (43) |
| Upper airway / oral | 2 (29) |
| Gastrointestinal tract | 1 (14) |
| Bladder | 1 (14) |
| Presenting symptom, n (%) | |
| Local pain | 16 (47) |
| Spinal cord compression | 3 (9) |
| Swelling | 2 (6) |
| Pathologic fracture | 2 (6) |
| Incidental | 1 (3) |
| Other | 10 (29) |
| Paraprotein at diagnosis, n (%) | |
| Paraprotein present | 18 (53) |
| Immunoglobulin G | 13 (72) |
| Immunoglobulin A | 4 (22) |
| Lambda only | 1 (6) |
| Treatment modality, n (%) | |
| Surgery only | 2 (6) |
| Surgery plus radiotherapy | 5 (15) |
| Radiotherapy only | 26 (76) |
| None | 1 (3) |
| Treatment outcome following radiotherapy, n (%) | |
| Complete response | 24 (77) |
| Partial response | 2 (7) |
| Information not available | 5 (16) |
| Local relapse | 2 (6.5) |
| Progression to myeloma, n (%) | 13 (38) |
| Second malignancy, n (%) | 4 (12) |
| Lung cancer | 2 (6) |
| Haematological malignancies | 2 (6) |