MRI features of a presumed noncolloidal intraventricular cyst in a young cat

A 5‐month‐old, male entire, Abyssinian cat was referred for investigation of 1‐week history of lethargy and suspected neck pain. Neurological examination revealed severe obtunded mentation, intermittent opisthotonic posture, ambulatory tetraparesis, positional vertical nystagmus and neck hyperesthesia. Haematology and biochemistry profile were within normal limits. MRI of the head revealed bilateral ventriculomegaly of the lateral ventricles. The left ventricle was more severely dilated and contained a large intraventricular cyst‐like structure bordered by a thin membrane. The cystic lesion caused a marked mass effect with mild‐line shift, cerebellar compression as well as caudal transtentorial and foramen magnum herniation. A congenital intraventricular cyst was suspected based on MRI findings.