Pagetoid reticulosis (Woringer-Kolopp disease).

Pagetoid reticulosis (Woringer-Kolopp disease) is a rare subtype of cutaneous CD8-positive T-cell lymphoma. A 41-year-old man presented with a 7-year history with a slowly progressive erythematous plaque on his right buttocks. With the working diagnosis of psoriasis, he was treated with topical corticosteroids which produced no improvement. Histological examination showed an epidermotropic T-cell lymphoma with predominance of CD8- vs.CD4-positive lymphocytes. Based on the clinical picture and the histological findings, we diagnosed pagetoid reticulosis. Excision of the plaque and cream PUVA photo-chemotherapy produced long-term remission.