Clinical Response of Necrobiotic Xanthogranuloma to Treatment of Underlying Paraproteinemia with Lenalidomide

Necrobiotic xanthogranuloma (NXG) is a rare, chronic, histiocytic panniculitis associated with underlying paraproteinemia. This paraproteinemia, with monoclonal gammopathy of undetermined significance (MGUS), may be followed without treatment. We report a 62-year-old female with a history of progressive nodular and ulcerated lesions for many years who failed local and intralesional treatments. The skin lesions progressed to ulceration. Her paraprotein levels reduced when the underlying monoclonal gammopathy was treated with lenalidomide and dexamethasone. Healing and resolution of the skin lesions was seen in conjunction with reduction in serum paraprotein levels. Symptomatic skin lesions warrant treatment of the underlying paraproteinemia in the patient with NXG and MGUS. Treatment with lenalidomide and dexamethasone was successful in this patient.