Epitheliotropic cutaneous lymphoma in a Javan silvered leaf monkey (Trachypithecus auratus auratus) and attempted treatment with masitinib

Abstract A 14‐month‐old, female Javan silvered leaf monkey ( Trachypithecus auratus auratus ) was presented for inguinal circular, erythematous, crusty dermatitis. The animal was bright and alert, and appetite was good. Lesions progressed to the whole abdomen and became ulcerative. Skin biopsies revealed a cutaneous lymphoma and no metastases were detected on computed tomography scan. Anti‐tumoral treatment was attempted with masitinib (50 mg orally every 48 hours), a tyrosine kinase inhibitor. In the absence of improvement of the lesions, as treatment was well tolerated, masitinib dose was increased to 50 mg orally once a day. Effect on the lesions was minimal, clinical condition worsened and the animal died 9 months after initial presentation. Postmortem examination and histopathology confirmed multicentric epitheliotropic CD3 + cutaneous lymphoma. To the authors’ knowledge, this is the first report of cutaneous lymphoma in a langur, and the first attempt of treatment with masitinib in a non‐human primate species. Despite poor response, masitinib treatment appeared safe.