Choroid plexus carcinoma in a horse: case report

ABSTRACT: Neuroepithelial neoplasms present in the ventricular system originate from the cells lining the choroid plexus and can be benign or malignant, such as choroid plexus carcinoma. A four-year-old equine presenting with a fifteen-day history of neurological symptoms was sent for veterinary evaluation. Upon examination, the horse exhibited apathy, severe ataxia, head tilt, circling behavior, head pressing, decreased tail tone, anosmia, absence of menace response, lack of facial sensitivity, and lingual hypotonia. Cerebrospinal fluid analysis revealed mixed pleocytosis, increased protein, and decreased glucose. Following the animal’s death, histopathological and immunohistochemical examinations confirmed the diagnosis of choroid plexus carcinoma in the third ventricle. It is concluded that horses may develop central nervous system tumors, such as choroid plexus carcinoma, with nonspecific clinical symptoms, ineffective clinical treatment, and a conclusive diagnosis established postmortem.