A 64-year-old man is found to have an IgG kappa M-protein of 28 g/L and bone marrow plasma cells of 12%. He has no anaemia, hypercalcemia, renal impairment, bone lesions, or clonal plasma cell related symptoms. Serum free light chain ratio is normal. Best next step?

• A Start lenalidomide-dexamethasone induction
• B Local radiotherapy to the spine
• C Immediate autologous stem cell transplant
• D Observation with monitoring every 3 to 6 months ✓

Explanation

An M-protein of 30 g/L or more, or marrow plasma cells of 10% or more, without CRAB features or biomarkers of malignancy defines smouldering multiple myeloma, managed with close surveillance every 3 to 6 months. Treatment is deferred until progression to active myeloma occurs. Chemotherapy or transplant without symptomatic disease exposes him to toxicity without proven survival benefit, and radiotherapy addresses solitary plasmacytoma, which is not present here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.