Generalized papular xanthomatosis in mycosis fungoides.

Xanthomas can occur in association with underlying lymphoproliferative disease, or they can result from lipid deposition in damaged or altered skin. We report a case of generalized papular xanthomas that developed in a patient with Sézary syndrome. The xanthomas were composed of foamy histiocytes that were shown by immunoperoxidase staining to be of the monocyte/macrophage lineage. Electron microscopic studies revealed lipid vacuoles, lysosomes, and myelin figures but no Birbeck granules, features that are consistent with a non-X histiocytosis. Generalized papular xanthomatosis has not been previously described in a patient with cutaneous T-cell lymphoma.