Necrobiotic xanthogranuloma treated with chlorambucil

We report a case of necrobiotic xanthogranuloma that responded to treatment with chlorambucil. A 56-year-old man presented with a 5-year history of multiple, mildly pruritic, brown-to-violaceous plaques with central ulceration and atrophy involving the periorbital area, extremities, and trunk. Laboratory studies showed mild leukopenia and a monoclonal gammopathy of the IgG lambda type on serum protein immunoelectrophoresis. Histopathological evaluation revealed a dense histiocytic infiltrate with hyaline necrobiosis involving the dermis with extension to the subcutis. Multiple large multinucleated giant cells and scattered lymphocytes were seen. A diagnosis of necrobiotic xanthogranuloma was established. The patient was started on chlorambucil initially at 2 mg per day. The dose was later increased to 4 mg per day, which resulted in flattening and complete resolution of his skin lesions.