Brain Lesions Cancer

Brain tumors seem to be more base in dogs than cats, and definite breeds are over represented such as Boxers, Golden Retrievers, Dobermans, Scottish Terriers and Old English Sheepdogs.

Brain Lesions Cancer

Primary vs Secondary

Brain tumors can be former or secondary (metastasis from other sites). former brain tumors are normally solitary, the most base ones in the dog being gliomas and meningiomas. In cats, the most base type are meningiomas and these can occur at multiple locations.

Secondary tumors in dogs include postponement of a nasal tumor, metastases from breast, lung or prostate cancer, hemangiosarcoma or postponement of a pituitary gland tumor. Nerve sheath tumors and skull tumors have also been reported. Secondary tumors in cats include pituitary gland tumors, metastatic carcinomas, local postponement of nasal tumors, skull tumors and middle ear cavity tumors.

What causes a brain tumor?

The cause of brain tumors is not known. Diet, environment, chemical, genetic, viral, immunologic and trauma have all been considered. In cats with meningiomas, because they often occur in very young animals, a genetic element is suspected.

Benign vs Malignant

The terms benign and malignant must be used with care when referring to brain tumors. normally these terms apply to various characteristics on a cellular level, but on a biological level, even benign brain tumors can kill the animal due to the secondary effects like increased intracranial pressure or cerebral edema. In short, any brain tumor can kill.

What are the symptoms?

There can be huge range here. Many animals will present with vague signs, such as one or any of the following:

1. Loss of trained habits

2. Decreased levels of activity

3. Decreased frequency of purring in cats

4. Disorientation

5. Blurring More specific symptoms are dependent upon where exactly the tumor is placed within the brain, the size of the tumor and how fast it is growing. As a tumor enlarges, symptoms tend to come to be more severe. These can include:

6. Seizures (often indicate a tumor in the cerebral cortex)

7. Facial paralysis (may indicate a brainstem tumor)

8. Tremors (may indicate a tumor in the cerebellum)

9. Wobbliness (may indicate a tumor in the cerebellum)

10. Full or partial blindness (may indicate tumor in hypothalamus or optic nerve)

11. Loss of smell (may indicate tumor of olfactory system)

The corporeal presence of the tumor can cause knock on effects due to inflammation and edema of the surrounding area. This can cause symptoms such as:

12. Changes in behaviour or temperament (irritability, lethargy)

13. Compulsive walking

14. Circling

15. Pressing head against a wall or hard surface

Animals can sometimes carry brain tumors for any years before presenting to a veterinary clinic, if the tumor is slow growing. In these cases the symptoms establish gradually, and the owner tends to get used to them so that by the time the animal is examined, the tumor has reached a indispensable size.

How is a brain tumor diagnosed?

History and Clinical Examination

The first step for a veterinarian is to take a proper history of all of the clinical signs, and when they developed. This is followed by a full general clinical exam and a full neurological examination.

Bloods

After that, blood should be taken for disposition haematology and biochemistry profiles. This is to look for any disease exterior the brain. Results will be general for brain tumors, with the potential exception of some pituitary gland tumors.

Radiography

Plain skull radiographs (xrays) under general anesthetic have small value in detecting a brain tumor, but they can be beneficial if there is a tumor in the nasal cavities or the middle ear which could enlarge into the skull. On rare occasions, they can identify bony changes in the skull which can accompany a brain tumor, or mineralization within the tumor itself. Radiographs and ultrasound of the chest and abdomen are beneficial to look for a tumor elsewhere in the body, in cases where the brain tumor is a secondary metastasis.

Mri and Ct Scans

Confirmation of a brain tumor can is normally only achieved using the industrialized imaging techniques, Ct scans or Mri. Both of these have pros and cons when compared to one another. Ct is better for bony changes, while Mri is better for soft tissue definition, for the detection of many of the knock on effects of brain tumors such as edema, cysts and bleeding. Mri is the adored selection for diagnosing former brain tumors.

Biopsy

This is the only way to definitively diagnose a brain tumor. The industrialized imaging techniques above offer much information, but they can occasionally confuse a tumor with a non cancerous mass or a cyst, and they also do not tell us the exact type of tumor present, and therefore the proper medicine and prognosis. The best type of biopsy is the Ct guided stereotactic brain biopsy system, which is rapid, strict and quite safe. Since exploratory surgery is high risk, it is not normally attempted unless there is a uncostly chance of removing the whole tumor with minimal collateral damage. Many brain tumors in cats and dogs are not categorized on a cellular level until post mortem.

Cerebrospinal Fluid (Csf) Analysis

Csf prognosis is beneficial for ruling out inflammatory causes of the symptoms, but tumor cells are rarely identified here. Increased levels of white blood cells and increased protein levels may be present in the Csf with many brain tumors, though this is not diagnostic. This test can be high risk when intracranial pressure is increased, as brain herniation can occur.

Treatment

Treatment is aimed at being either curative or palliative. curative medicine eradicates the tumor or reduces its size, whilst palliative therapy reduces the surrounding cerebral edema and slows down the increase of the tumor. Palliative therapy also involves administering antiepileptic drugs, if seizures are occurring as a consequent of the tumor.

Surgery

Whether this is an selection depends on the general condition of the animal, and the strict location, size, extent, invasiveness and nature of the tumor. Tumors such as meningiomas in cats can be removed successfully by surgery. However, surgery to remove tumors in definite locations such as the brainstem can be highly dangerous, perhaps resulting in death. Even partial removal can advantage the animal though, particularly if the tumor is slow growing.

Radiotherapy

This is probably the most widely used form of medicine for brain tumors. Radiation therapy can be used alone or in compound with other treatments. It is also beneficial in the medicine of secondary brain tumors. The aim is to destroy the tumor without harming the general tissue too much.

Chemotherapy

The main problem with chemotherapy for brain tumors is that many drugs do not cross the blood brain barrier. In addition, the tumor may only be sensitive to high doses, doses which are toxic to general brain tissue and therefore unsuitable for use. However, any drugs have been used for this purpose that can cross the blood brain wall with reported success, along with cytosine arabinoside, lomustine and carmustine.

Probable Outcome

Studies of animals that receive palliative medicine (corticosteroids) for brain tumors show a survival range post prognosis of 64 to 307 days. This demonstrates the inability to accurately predict life expectancy in these cases. What is definite is that the survival times significantly increase with surgery, radiotherapy or chemotherapy. Radiation therapy seems to offer the best results, alone or in compound with other treatments. Generally, the more severe the symptoms, the shorter the life expectancy.