Diffuse, bilateral intraventricular spread of an oligodendroglioma in a Boxer dog

A case of a high‐grade oligodendroglioma in a boxer dog is presented. Using magnetic resonance imaging, a parenchymal lesion was noted entering into the ventrocaudal, right lateral ventricle. Magnetic resonance imaging showed the mass had extensive, contiguous spread rostrally through the lateral ventricles, and caudally into the third and fourth ventricles, and central canal. This was confirmed with histopathology. This degree of invasion in the ventricles by an oligodendroglioma has not been reported and indicates that oligodendrogliomas should be included as a differential diagnosis for intraventricular tumours with bilateral, contiguous invasion of the ventricular system.