Monoclonal gammopathy of clinical significance in a young patient treated with melphalan-thalidomide-prednisone.

Key Clinical Message: We report an observation of a young patient presenting with severe type 1 cryoglobulinemic vasculitis revealing a monoclonal gammopathy of clinical significant. Treatment with Melphalan-Thalidomide Prednisone improved the symptoms. Early diagnosis would prevent serious tissue damage. Abstract: Monoclonal gammopathy encompass diverse clinical forms. Only the cancerous form, multiple myeloma (MM), is treated based on specific diagnostic criteria. A new clinical entity, monoclonal gammopathy of clinical significance (MGCS), warrants special attention due to its need for specific treatment. It involves patients with signs of potentially severe organ involvement that do not meet MM criteria. We present the case of a 34-year-old Malagasy woman with severe type I cryoglobulinemic vasculitis associated with noncancerous monoclonal gammopathy, showing a favorable outcome after treatment with Thalidomide. Symptoms included toe necrosis, a severe ulcer on the left calf evolving for 3 months, and stocking-like dysesthesias. Investigations revealed monoclonal gammopathy at 30.1 g/L, proteinuria at 1 g/24 h, medullary plasma cell at 6%, and circulating cryoglobulin of Ig kappa type. CRAB criteria (anemia, hypercalcemia, renal insufficiency, and osteolysis) were absent. Treatment with Thalidomide, combined with corticosteroids and local care for 4 months, resulted in ulcer healing, disappearance of dysesthesias, and persistent normalization of gammaglobulin. Our case underscores the importance of specific treatment for MGCS.