A case report: Nonsecretory multiple myeloma presenting with bone pain.

RATIONALE: Nonsecretory multiple myeloma (NSMM) is a rare subtype of multiple myelom, occurring in 1% to 2% of multiple myelom and characterized by the inability of clonal plasma cells to synthesize or secrete immunoglobulins. We describe a 71-year-old male patient who began with bone pain and was referred to hospital several times, but was not properly diagnosed and effectively treated.

PATIENT CONCERNS: A 71-year-old male patient visited our hematology department, complaining of lumbago for 1 year and back pain for half a year.

DIAGNOSES: Low-dose whole-body bone computed tomography: multiple bone destruction of the sternum, ribs, multiple vertebrae and accessories of the spine, pelvis, bilateral humerus, and proximal femur. Monoclonal plasma cells accounted for 17.5% of nuclear cells in bone marrow puncture smear. Fluorescence in situ hybridization detected amplification of CKS1B (1q21) gene. Immunofixation electrophoresis negative. About 10.72% of monoclonal plasma cells were detected by flow cytometry. Finally, he was diagnosed with NSMM.

INTERVENTIONS: The patients received VCD chemotherapy (bortezomib 1.3 mg/m2, d1, d4, d8, d11; cyclophosphamide 300 mg/m2, d1-2, d8-9; dexamethasone sodium phosphate 20 mg, d1-2, d4-5, d8-9, d11-12, once every 21 days).

OUTCOMES: After 2 cycles of VCD treatment, the symptoms of bone pain were significantly relieved, and the efficacy was evaluated as partial response. Follow-up chemotherapy will continue to be completed on schedule. We will continue to follow up to further evaluate the overall survival and progression-free survival.

LESSONS: This case shows that NSMM is easily missed or misdiagnosed.