Diffuse plane xanthomata.

An 80-year-old woman presented with yellow-orange papules and plaques on her scalp, back, and arms, with a Koebner reaction of the lesions on her back. Clinical and histopathologic findings were consistent with the diagnosis of diffuse plane xanthoma. Laboratory data showed normal lipid levels and an abnormal paraprotein in the blood. A bone marrow biopsy specimen was normal. Diffuse plane xanthoma is frequently associated with reticuloendothelial disorders, which may appear several years after the skin findings. Treatment is limited but may include the use of ablative lasers.