Disseminated necrobiotic xanthogranuloma: A cutaneous manifestation of monoclonal gammopathy

Abstract

A 67-year-old woman presented with an 8-month history of multiple cutaneous lesions. Dermatological examination revealed firm, infiltrated plaques and nodules ranging in color from yellowish-brown to erythematous-violaceous, with dark brown areas, irregular, polycyclic, and arcuate borders, and a tendency to coalesce. The lesions predominantly involved the breasts and thoracoabdominal region, with additional lesions on the arms, neck, and periocular area. Figure 1 shows extensive confluent plaques with areas of central clearing and a rounded lesion with a crusted surface on the lower abdomen. This chromatic variability is consistent with necrobiotic xanthogranuloma, whose lesions do not invariably exhibit the characteristic yellow-orange discoloration.