BACKGROUND Necrobiotic xanthogranuloma (NXG) is a rare chronic disorder characterized by firm yellow to red-orange nodules and plaques affecting the face, abdomen, and extremities with the potential for systemic involvement. NXG has a close association with monoclonal gammopathies, and there is a predilection for the development of multiple myeloma. Treatment options are varied due to inconsist...

RATIONALE Xanthomatosis associated with monoclonal gammopathy includes hyperlipidaemic xanthoma (HX), normolipidaemic xanthoma (NX) and necrobiotic xanthogranuloma (NXG). All three pathologies are characterized by skin or visceral lesions related to cholesterol accumulation, monoclonal immunoglobulin (MIg) and hypocomplementemia. The pathophysiology underlying NXG remains unknown although the i...

oids (5, 6). In our patient the titre of circulating anti-ICS antibodies was low, which might indicate a prolonged initial phase of PV before generalized development of bullae. The massive plasma cell in®ltrate seen in the lesional upper dermis may be a factor for the localization of the lesions. Another possibility is that an unknown mechanism prevents the generalization of PV, resulting in th...