The sign of Leser-Trélat is characterizedby the sudden appearance of seborrheic keratosesassociated with an underlying malignancy. An elderly man who developed multiple new-onsetseborrheic keratoses temporally associated witha diagnosis of mycosis fungoides is described andlymphoma-associated Leser-Trélat sign is reviewed. Pubmed was used to search the followingterms: cutaneous T-cell lymphoma, Leser-Trélat,leukemia, lymphoma, mycosis fungoides, and Sézarysyndrome. Papers with these terms and referencescited within these papers were reviewed. An 84-year-old man developed multiple seborrheickeratoses temporally associated with a diagnosisof mycosis fungoides is presented. He was treatedwith bexarotene and achieved clinical remission;the number of seborrheic keratoses also decreased.Lymphoma-associated Leser-Trélat sign has beenobserved not only with mycosis fungoides but alsoother lymphomas and leukemias. Thesign of Leser-Trélat is predominantly associated withsolid organ adenocarcinomas. Albeit less common, aneruptive onset of seborrheic keratoses can also occurin association with hematopoietic malignancies.