Abstract

Cutaneous CD8-positive cytotoxic T-cell lymphomas are rare entities. Among these neoplasms, primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma accounts for <1% of primary cutaneous T-cell lymphomas. Here, we present a case of a cutaneous cytotoxic T-cell lymphoma in a 70-year-old man. The patient presented with erythematous papules and plaques on the chest and arm that raised clinical suspicion for Sweet syndrome. At the time of presentation, the patient had no known lymph node or systemic involvement by a neoplastic process. Histopathologically, there was an atypical lymphoid infiltrate that primarily involved the papillary dermis, with focal epidermotropism as well as extension to the reticular dermis and subcutaneous tissue. The atypical lymphocytes were intermediate in size and displayed open chromatin, small nucleoli, irregular nuclear contours, and mitotic activity. Immunohistochemistry was performed, and the cells expressed CD3, CD5, CD8, TIA1, and TCR beta-F1. CD7 was significantly diminished, and CD30 was negative. The abnormal lymphocytes did not express CD2, CD4, TCR delta, or TdT. Chromogenic in-situ hybridization for EBER was negative. A clonal T-cell receptor gene rearrangement was detected by PCR studies. No follow-up information was available for this case. Taken together, the histopathology and the clinical presentation – eruptive papules and sparing of lymph nodes – were most consistent with a primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma rather than another cutaneous lymphoma or cutaneous involvement by a peripheral T-cell lymphoma, not otherwise specified. We present this case to highlight this rare entity, discuss its typical features, and contextualize it among cytotoxic T-cell lymphomas involving the skin.

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