Indolent CD8+lymphoid proliferation of the ear: A phenotypic variant of the small-medium pleomorphic cutaneous T-cell lymphoma?

Background Recently, Petrella et al. described four patients with an unusual CD8+ lymphoid proliferation arising on the ear. These cases do not correspond clearly to any recognized category of cutaneous T-cell lymphoma (CTCL) described in the World Health Organization (WHO)/European Organization for Research and Treatment of Cancer (EORTC) 2005 classification. Methods and Results Three patients (all men; median age 64; range: 61-69) presented with plaques or small tumors localized on the ears. All lesions showed histopathologically a dense, diffuse infiltration of lymphocytes within the entire dermis without epidermotropism. Cytomorphology revealed predominance of medium-sized pleomorphic lymphocytes. Immunohistochemistry showed a cytotoxic phenotype (CD3 + /CD4 - /CD8 +). Polymerase chain reaction (PCR) analysis of the T-cell receptor (TCR)-gamma gene revealed a monoclonal rearrangement in two of three patients. Follow-up data of two patients were available; one is alive without skin or systemic manifestations of the disease after 28 months, whereas the other is alive with persistent skin disease after 7 months. Conclusions Our observation confirms that some patients present with a peculiar lymphoid proliferation of small-medium pleomorphic cytotoxic lymphocytes located on the ear, probably representing a phenotypic variant of the cutaneous small/medium pleomorphic T-cell lymphoma (CSMPTCL). These cases should not be misinterpreted as a high-grade cytotoxic lymphoma. Beltraminelli H, Mullegger R, Cerroni L. Indolent CD8+ lymphoid proliferation of the ear: A phenotypic variant of the small-medium pleomorphic cutaneous T-cell lymphoma?.