Diffuse iris melanoma leading to secondary glaucoma in a lion (Panthera leo)-A case report

To describe the case of a 12-year-old male African lion (Panthera leo) presented with ocular discharge, corneal edema, and buphthalmos of the right eye.

Ocular ultrasonography showed an intraocular mass involving the iris and ciliary body. Enucleation was performed.

Subsequent histopathological analysis revealed a pleomorphic pigmented neoplastic cell population infiltrating, expanding and effacing the iris and ciliary body and occupying the ciliary cleft. The histopathological and immunohistochemical features were consistent with a diffuse iris melanoma (DIM).

DIM is the most common primary intraocular neoplasm of domestic cats, but rarely reported in large felids. The prognosis in large felids is unknown and warrants identifying additional cases and careful monitoring of affected individuals.