A 59-year old man with no evidence or history of hyperlipidemia had a dystrophic xanthoma, and accumulation of lipid-rich foam cells in an area of damaged or abnormal skin, that was associated with untreated mycosis fungoides (MF). The patient was subsequently treated with whole-body electron beam therapy. This association of MF and dystrophic xanthoma illustrates histiocyte and xanthoma cell interaction in MF, a cutaneous T-cell lymphoma. Xanthomas may be a cutaneous sign of an underlying lymphoproliferative or myeloproliferative disease in normolipemic patients.