Pagetoid Reticulosis with Double-Negative CD4/CD8: A Rare Case Report

Pagetoid Reticulosis (PR) is a rare variant of mycosis fungoides, characterized by localized patches or plaques mainly on the distal extremities with intraepidermal proliferation of neoplastic T cells. Typically, PR exhibits a CD4-positive, CD8-negative immunophenotype, whereas a CD4–/CD8– double-negative profile is distinctly uncommon, yet in localized pagetoid reticulosis it may be associated with an indolent clinical course and favorable therapeutic response. In this report, we present a case of a healthy 58-year-old male with a three-year history of a persistent erythematous plaque on the left forearm. Histopathological analysis demonstrated atypical lymphocytes with prominent epidermotropism. Immunohistochemical staining showed double-negative CD4/CD8 phenotype with positive CD3, CD5, and CD7. The lesion responded completely to topical therapy followed by localized radiotherapy, with clinical remission at follow-up.