Bath Vet ReferralsCase presentation
An 8 year old female neutered Boxer presented with a history of recent onset generalised seizures. Physical and neurological examinations were unremarkable.

Question. What is your neurolocalisation?
Question. What are your most likely differentials?

For further investigations, imaging, diagnosis and the answers to these questions, please scroll down the page.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Question. What is your neurolocalistion?
Answer. Seizures suggest forebrain disease.

Question. What are your most likely differentials?
Answer. The breed and age are suggestive of neoplasia. Other differentials include metabolic disease, immune-mediated disease, infectious disease and late onset idiopathic epilepsy.

 

 

 

 

Further investigations
Routine haematology, biochemistry and protozoal serology were unremarkable. MRI of the brain was performed (fig 1.) which showed a poorly contrast enhancing mass, which was bright on T2, in the left forebrain.


Fig 1. T2 weighted transverse MRI scan of brain. There is a large hyperintense mass in the left cerebral hemisphere, which is showing some mass effect as evidenced by compression of the lateral ventricle. Note the black shadow in the bottom left of the picture, which is artefact due to the metal spring in the cuff of the endotracheal tube.

Diagnosis
Brain tumour

Question: What is the likely type of tumour, and what is the best treatment?

For the answer to this question, please scroll down the page.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Question. What is the likely type of tumour, and what is the best treatment?
Answer. Boxers are prone to develop gliomas. They can also get meningiomas, but these tend to have a good, homogenous contrast uptake, whereas gliomas usually poorly enhance or show a ring enhancement. Histopathology is necessary to be certain of the diagnosis however. Gliomas are invasive tumours and surgical removal is rarely indicated. Treatment options include palliation with steroids to reduce peritumoural oedema, chemotherapy with lomustine, and radiotherapy. Radiotherapy is generally well tolerated, and can lead to durable remissions. 

 

 

 

 

 

Treatment and follow up
Treatment consisted of radiotherapy plus phenobarbitone. Seizures resolved, and the phenobarbitone was weaned off.

MRI was performed 6 months after the radiotherapy which showed the tumour was no longer evident (see fig 2).


Fig 2. T2 weighted transverse MRI of the same Boxer as in figure 1, 6 months after radiotherapy.

Discussion
Boxers are strongly predisposed to develop gliomas, and Boxers that develop seizures, even if they are less than 6 years old, should be considered for MRI imaging to aid in reaching a diagnosis. There are several treatment options, but radiotherapy, where available, probably gives the longest survival times, and is usually well -tolerated.