Nerve Sheath Tumor in Cats

Every organ uses a nerve system to send information to the brain. Nerve sheath tumors disrupt this function and cause problems for your cat. The tumors can affect any area of the body containing a nerve system. There are tumors that metastasize, but most of the tumors remain in one area.

Benign and malignant tumors should be treated immediately, and it is especially important to treat the malignant tumors before they cause paralysis or even death.

There are many names for nerve sheath tumors, such as schwannoma, neurofibrosarcoma, and hemangiopericytoma. The tumors should not be taken lightly as they can result in pain, difficulty breathing, and paralysis. White lumps usually appear on a cat that is suffering from nerve sheath tumors.

Clinical signs depend on the type and location of the nerve sheath tumor. You may notice white lumps on the skin in the affected area. The following symptoms are also signs of nerve sheath tumors in cats:

• Pain
• Difficulty breathing
• Weakness of limbs
• Loss of muscle
• Weight loss
• Abdominal swelling
• Difficulty urinating
• Low blood sugar
• Paralysis
• Facial paralysis on one side
• Smaller pupils
• Abnormal or droopy eyelids
• Horner's syndrome

Types

Your cat is at risk of developing two types of nerve sheath tumors:

• Neurofibromas and schwannomas: Tumors are benign and do not usually metastasize.
• Neurofibrosarcomas and malignant schwannomas: Tumors are malignant and grow quickly, and they usually do metastasize.

Whether the tumor is benign or malignant, it is important to have the condition treated immediately. The key is to bring comfort to your cat and stop the tumors from growing or spreading.

The cause of nerve sheath tumor in cats is usually idiopathic. However, younger cats and very few older cats may develop the tumors due to feline sarcoma retroviruses. Older cats do not usually develop the tumors from the retrovirus because they have already built an immunity to it, so the cause of nerve sheath tumors in most older cats is idiopathic.

Your veterinarian performs a physical exam to check the overall health of your cat. This may include blood work, an electrolyte panel and a urinalysis. Your veterinarian may carefully inspect the area for white lumps. Expect your veterinarian to ask questions about symptoms and medical history. If your cat has suffered from a feline sarcoma retrovirus, this may give your veterinarian an idea of how the nerve sheath tumors developed.

Your cat will need to undergo additional tests to confirm and evaluate the nerve sheath tumors. Your veterinarian may order x-rays and an ultrasound to reveal abnormal lumps, and an electromyogram may reveal abnormal activity of the muscles. It is likely that your veterinarian will order an MRI or CT to check the location and extent of the tumors.

A histopathology is a very important test in which your veterinarian obtains a sample of the tumor. The sample is submitted to a veterinary pathologist for examination. Your veterinarian then receives information regarding the tumor itself, such as the name, behavior, and prognosis.

Your veterinarian will discuss treatment options based on the location, type, and extent of the nerve sheath tumors.

Surgical Removal of Tumors

The most common treatment is surgically removing the tumors from the affected area. There is a chance the tumors could reoccur after the surgery, so your veterinarian may only explore this option if the tumors are benign. This also allows your veterinarian to get a closer look at the benign tumors.

Surgical Removal of Limb

Unfortunately, there are many cases that involve the surgical removal of the limb itself. Amputation of the limb is only necessary when the actual tumors cannot be removed. 

Radiotherapy 

Radiotherapy is usually suggested if your veterinarian cannot remove the tumors or limb. It is also an option if there are any tumors left behind after the surgery. Radiotherapy is used to stop growth, shrink, or eliminate the tumors. This is usually a last resort when the surgery is not an option or not completely successful.

Follow-up appointments are necessary after treatment of nerve sheath tumors. This allows your veterinarian to check the progress of the tumors and ensure they have not returned. If the tumors do reoccur, your veterinarian will discuss further treatment options with you. Your veterinarian also needs to make sure your cat is not suffering from negative side effects of the treatment. Remember to follow any instructions given by your veterinarian.

The prognosis depends on the type and location of the tumor, and it usually ranges from guarded to good.