Necrobiotic xanthogranuloma (NXG) is a rare, chronic, progressive, non-Langerhans histiocytosis that is strongly associated with hematologic malignant conditions. Only about 100 cases have been reported in the literature since it was first described in 1980. It is important for dermatologists to recognize NXG and initiate a prompt hematologic evaluation. IgG kappa is the most frequently discovered monoclonal gammopathy (65%), followed by IgG lambda (35%), and, much less commonly, IgA. Although no modality has been shown to be consistently effective, therapeutic options include glucocorticoids (topical, intralesional, and/or systemic), alkylating agents (chlorambucil and cyclophosphamide). interferon alpha, antimetabolites, antibiotics, thalidomide, and plasmaphersis.