Proceedings 31st Symposium ESVN-ECVN

Cerebellar degeneration (CD) or abiotrophy is the premature degeneration of the cerebellar cell population, caused by a probable intrinsic metabolic abnormality and is considered a rare neurologic condition in domestic cats. Lymphoma is mentioned as the second most frequent intracranial neoplasm in young cats. In humans, CD is reported as a rare paraneoplastic syndrome in children with Hodgkyn's lymphoma. CNS Lymphoma associated with CD has not been reported in small animals previously. The present report includes an 8‐months‐old male, shorthair domestic cat presented with clinical signs of altered consciousness, symmetric ataxia, vertical positional nystagmus, mydriasis, strabismus, intention tremor of the head, and increased patellar reflexes. Neuroanatomic diagnosis indicated a diffuse cerebellar lesion. Blood count analysis showed thrombocytopenia and lymphopenia. Cerebrospinal fluid analysis indicated mononuclear and neutrophilic pleocytosis. Contrast CT imaging revealed multiple hypodense heterogeneous areas in both cerebral hemispheres, mild ventriculomegaly at the level of the caudal fossa, and a circular sharply marginated, homogeneously hyperdense mass occupying the right cerebellar hemisphere. Post‐mortem study indicated a 5 mm x 1 mm mass in the right cerebellar hemisphere close to the vermis. Histopathological analysis showed diffuse and severe loss of Purkinje cells with a decrease in the density of granular cells and moderate gliosis. Additionally, numerous neoplastic lymphoid cells were observed in the infiltrated mass consistent with a diagnosis of lymphoma. Inmunohistochemestry revealed expression of CD20 and a B‐cell inmunophenotype. This report is the first described case of possible paraneoplastic cerebellar abiotrophy associated with CNS lymphoma in a cat.