Sézary syndrome with CD3+CD4+CD8− immunophenotype in a Bichon Frise

Abstract

AbstractAn adult female spayed Bichon Frise with history of chronic pruritus, atopy and intermittent ear infections was presented for the assessment of generalised erythema, multiple cutaneous nodules, otitis externa and exudative dermatitis only partially and temporarily responsive to oclacitinib and systemic antibiotic treatment. Several investigations were performed, and a diagnosis of cutaneous epitheliotropic lymphoma (CETL) with circulating neoplastic lymphocytes (Sézary syndrome [SS]) with CD3+CD4+CD8− immunophenotype was obtained. The patient was treated with a single dose of L‐asparaginase and then continued on prednisolone only. After 300 days following the initial diagnosis, the dog was humanely euthanized due to disease progression. To our knowledge, this is the first case reported in the literature of a dog with SS with circulating neoplastic T lymphocytes expressing CD4 (T‐helper cells) rather than the more commonly reported CD8+ (T‐cytotoxic) phenotype.