Necrobiotic xanthogranuloma: a report of four cases.

Four patients are described who demonstrate the range of clinical and pathological features seen in necrobiotic xanthogranuloma with paraproteinaemia (NXG). Each patient had the typical periorbital yellow plaques with numerous well demarcated yellow indurated plaques on the trunk. All four patients had evidence of paraproteinaemia. The histopathology showed diagnostic features of intense necrobiosis with xanthomatization, including touton giant cells and the bizarre angulated giant cells of NXG. Previously, the patients had been diagnosed as atypical necrobiosis lipoidica, and the distinction between NXG and other necrobiotic conditions is discussed.