Abstract
Primary cutaneous CD8+ aggressive cytotoxic T-cell lymphoma is a rare variant of cutaneous T-cell lymphoma (CTCL) that can present, mimicking other less severe skin conditions. Due to the nonspecific presentation of these lesions, misdiagnosis as a less indolent CTCL can occur. We present an unusual case of CD8 positive cytotoxic T-cell lymphoma in a 52-year-old male with persistent upper lip swelling. The initial skin lesion was diagnosed as Mycosis fungoides. Further imaging revealed involvement of the tongue, and the patient received EPOCH chemotherapy. Despite treatment, the disease process extended to involve the cervical lymph nodes, pancreas, and stomach. Microscopic examination of the lip showed an abnormal T-cell population with prominent epidermiotropism, that lacked both CD4 and CD8 expression. Biopsy of the tongue lesion showed extensive involvement by a diffuse atypical lymphoid infiltrate with marked epidermotropism and adnexotropism. Immunophenotyping showed an abnormal T-cell population with CD3, CD7, CD8, CD56, and cytotoxic marker expression. Molecular studies confirmed the same T-cell clonal peaks in the lip and the tongue. Mutational analysis detected JAK3 and p53 mutations but lacked JAK2 fusions. Copy number analysis detected losses and gains in multiple chromosomes. Biopsy of the stomach detected a CD8 cytotoxic T-cell population with prominent epitheliotropism. This is an unusual report of primary cutaneous CD8 positive peripheral T-cell lymphoma with preferential involvement of mucosal sites. The case suggests a mucocutaneous variant of primary cutaneous CD8 positive aggressive epidermotropic cytotoxic T-cell lymphoma, highlighting the diagnostic challenges inherent in diagnostic dermatopathology.