LAUSR

NL: necrobiosis lipoidica NXG: necrobiotic xanthogranuloma INTRODUCTION Necrobiotic xanthogranuloma (NXG) is a rare condition currently classified as a noneLangerhans cell histiocytosis and associated with an underlying paraproteinemia (most commonly IgG-k) in approximately 80% of patients. Recent diagnostic criteria have been proposed, including 2 major criteria of clinical and histopathologic features consistent with NXG and 2minor criteria of paraproteinemia, plasma cell dyscrasia, and/or other associated lymphoproliferative disorder and periorbital distribution of cutaneous lesions in the absence of a foreign body, infection, or other identifiable cause. Necrobiosis lipoidica (NL) is a rare, chronic granulomatous disease historically associated with diabetes mellitus, although the strength of that association has been called into question. Other reported associations include hypertension, dyslipidemia, and thyroid disease. It is almost exclusively seen on the lower extremities (98% of the anatomic locations specified) of women (84% of the affected patients), according to a recent multicenter retrospective review, and can be very difficult to treat. In this study, we report a patient with ulcerated, atrophic, yellowish, peripherally telangiectatic plaques on the bilateral lower extremities almost perfectly simulating NL that was, in fact, NXG from myelomawith an associated type 1 cryoglobulinemia.