Diffuse plane xanthoma developing in association with prior monoclonal gammopathy

Diffuse plane xanthoma is a rare form of non-Langerhans histiocytosis that typically presents as asymptomatic symmetric diffuse yellow macules and plaques on the periorbital skin, neck, upper trunk and flexures. Extracutaneous lesions may be noted in the oral cavity, eye, tendons, aortic valve,