Pagetoid reticulosis (PR), also named Woringer-Kolopp disease, is a low-grade primary cutaneous T-cell lymphoma that usually presents as a solitary, slowly enlarging erythematous or hyperkeratotic plaque on the distal areas of the extremities. Histopathologically, it is characterized by a dense, band-like infiltrate of atypical lymphocytes with prominent epidermotropism within a hyperplastic epidermis, and immunophenotypic studies show in most cases, a CD4-positive T-helper phenotype for the neoplastic lymphocytes. We describe an African man with a more than 20-year history of an acral lesion of PR, which was histopathologically characterized by lymphocyte immunophenotype consisting of CD8- and CD30-positive cells. We discuss the differential diagnosis with other primary cutaneous lymphoproliferative disorders showing similar immunophenotype. This case shows that CD30-positive PR should be included as a rare variant within the spectrum of CD30-positive primary cutaneous lymphoproliferative disorders. As in other primary cutaneous CD30-positive lymphoproliferative processes, lesions of CD30-positive PR show an indolent course and a benign biological behavior.
Histopathologically, it shows a prominent infiltrate of atypical lymphocytes within a hyperplastic epidermis. Immunophenotypic studies in lesions of PR have led to the recognition of different phenotypes for the large atypical epidermotropic lymphocytes. The CD4-positive T-helper phenotype appears the most common.