Linfoma B cutàneo primario de centro folicular con epidermotropismo

The most frequent primary cutaneous B cell lymphoma, according to the EORTC classification, is primary cutaneous follicle center cell lymphoma (PCFCCL). Clinical presentation of PCFCCL is variable, but lesions are usually located on the head and neck or trunk, and the course is usually indolent, with very infrequent extracutaneous dissemination. On histopathological exam, PCFCCL lesions are characterized by a nodular or diffuse infiltrate that almost always spares the epidermis and is composed of centrocytes and occasional centroblasts with abundant reactive T cells in initial stages. We report on a 67-year-old man with a papule on the back of the neck which was diagnosed as PCFCCL. Histopathological exam of the lesion also disclosed presence of dermal granulomas and marked B cell epidermotropism. A complete work-up ruled out extracutanous dissemination of the disease, and the patient was treated with surgical excision and radiotherapy, with no recurrence to date. Lymphocyte epidermotropism is a common histopathologic feature of cutaneous T cell lymphomas, but can also be found in cutaneous B cell lymphomas, where the B cell nature of the infiltrating lymphocytes is considered by some authors as very suggestive of the diagnosis.