Diffuse plane xanthomatosis (Q55050)

This is a rare normolipidaemic disease in which multiple flat xanthomatous macules and plaques develop in the skin in association with a monoclonal paraproteinaemia. The disease generally occurs in adults but rare cases in children have been reported. The xanthomata typically involve the eyelids, neck, upper trunk, buttocks and flexures. Serum lipids are usually normal. Nearly all patients have a circulating monoclonal paraprotein which in about half the cases is associated with a myeloproliferative disorder, especially multiple myeloma, granulocytic or lymphocytic leukaemia. The xanthomata arise as a result of perivascular deposition of lipoprotein–immunoglobulin complexes.