Malignant teratoid medulloepithelioma in a llama

A lesion was identified in the eye of a juvenile llama, and preliminary cli nical findings included anterior uveitis and an exudative retinal detachmen t suggestive of infectious disease. However, histopathologic evaluation of the enucleated globe revealed an intraocular neoplasm composed of primitive neuroepithelium forming ribbons, cords, and rosettes, heteroplastic elemen ts including spindle cells in a loose myxomatous matrix, and islands of wel l-differentiated hyaline cartilage. Immunohistochemically, neoplastic cells were positive for vimentin and neuron-specific enolase. Spindle cells were multifocally positive for desmin and muscle specific actin, indicating dif ferentiation towards myofibers. These findings are consistent with a diagno sis of malignant teratoid medulloepithelioma; an extremely rare ocular neop lasm that affects children and young animals.