Necrobiotic xanthogranuloma.

A 67-year-old man presented with a 13-year history of slowly enlarging yellow-red plaques on the face and lower extremity. A biopsy specimen was consistent with necrobiotic xanthogranuloma. Necrobiotic xanthogranuloma is a slowly progressive histiocytic disease that is associated with paraproteinemia in most cases; however, its pathogenesis remains unclear. Although there is no first-line therapy, anecdotal reports have shown variable benefit with chemotherapeutic agents.