Case of transitional meningioma in a dog

Abstract

Meningiomas are the most common intracranial primary brain tumours in dogs and cats. Neurological symptoms vary depending on the location of the meningioma in the brain. In dogs, the most common clinical symptom are seizures. Other symptoms include ataxia, blindness and behavioural changes. In the case of suspected brain cancer, the most reliable additional examinations are magnetic resonance imaging and computed tomography. They allow us in visualising the tumour itself and in evaluating the structures adjacent to the tumour. It has a considerable impact on the prognosis and enables planning of surgical laccess. A 10-year-old Belgian Shepherd was presented with strongly expressed neurological symptoms. CT examination revealed a heterogenous, hyperdense, oval focallesion with ill-definede dges and the following dimensions. The lesion was adjacent to the presphenoid bones, within the olfactory bulbs in the forebrain. After a CT scan of the brain, due to a clearly bad prognosis, the owner decided not to wake the animal up from anaesthesia and to euthanize it. During the autopsy of the animal, brain tumour fragments were collected for histopathological examination. Based on the histological features and presence of two types of cells that form the tumour structure, the observed mass was classified as a transitional (mixed) meningioma.