Pleomorphic CD8+ small/medium size cutaneous T-cell lymphoma

Pleomorphic small/medium-sized cutaneous T-cell lymphoma is a recently recognized rare type of cutaneous T-cell lymphoma which is clinicopathologically different from mycosis fungoides and Sezary syndrome. By definition the phenotype of the neoplastic lymphocytes in pleomorphic small/medium-sized cutaneous CD3CD4CD8 but CD8 pleomorphic small/medium sized cutaneous T-cell lymphoma cases have been occasionally described. We describe a 55-year-old female with a pruritic erythematous nodule on the lateral aspect of her right foot present for 1.5 years. Histology revealed a nonepidermotropic lichenoid infiltrate in the papillary dermis and a patchy infiltrate in the mid and lower dermis composed of small to medium-sized pleomorphic lymphocytes. The immunophenotype of these lymphocytes was CD3CD4CD8TIA-1. Staining for CD20, CD30, CD56, TdT, and LMP1 were negative, and the Ki-67 proliferation index was 5% to 10%. Gene rearrangement studies demonstrated a T-cell clone. The laboratory and imaging workup did not reveal extracutaneous involvement. The lesion was treated by local irradiation but a follow-up biopsy demonstrated only partial remission. Consequently, the lesion was treated by surgical excision.