Tumor of the Nerves in Cats

Nerve Sheath Tumor in Cats

Nerve sheath tumors are tumors that grow from the myelin sheath that covers the peripheral and spinal nerves. This type of tumor affects the nervous system of the body, as it compromises the functioning ability of the peripheral and/or spinal nerves that form the peripheral nervous system and which reside or extend outside the central nervous system (CNS). These tumors are rarely seen in cats.

Symptoms and Types

• Progressive and chronic lameness in forelimb (common symptom)
• Muscle wasting
• Decreased muscle tone
• Uncoordinated movements
• Limb weakness

Causes

The exact cause of this condition is still not known.

Diagnosis

You will need to give your veterinarian a thorough history of your cat’s health, including a background history and onset of symptoms. Your veterinarian will conduct a complete physical examination with laboratory tests, including complete blood count (CBC), biochemistry profile, and urinalysis. The results of these routine laboratory tests are usually within normal ranges. The cerebrospinal fluid (CSF), the protective and nourishing fluid that circulates around the brain and spinal cord, will also be tested, but the findings are usually non-specific. For confirmation of the diagnosis your veterinarian may need to take biopsy samples from the nerve sheaths using ultrasound guidance. Radiographic studies, including x-rays, magnetic resonance imaging (MRI), and computed tomography (CT-scan) will provide further information for a solid diagnosis. MRI is the most specific test for diagnosis of this disease.

Treatment

Your veterinarian may perform a surgical resection of the affected nerves. In some cases amputation of the affected limb will need to be performed in order to minimize the chances of a local recurrence of the tumor. More advanced surgical procedures will be required if it is necessary to perform the resection of nerve roots in the more delicate area of the spinal cord. Medications to reduce inflammation and edema (swelling) at the affected site will be prescribed, both to make treatment easier to perform and to make your cat more comfortable. Radiation following surgery can also be considered to decrease the chance of local recurrence. Whether to use radiation therapy or not will be decided by you and your veterinary oncologist.

Living and Management

After surgery, you should expect your cat to feel sore. Your veterinarian will give you pain medication for your cat to help minimize its discomfort. Keep in mind that pain medications must be used with caution, since one of the most preventable accidents that occur with pets is overdose of medication. Follow all directions carefully.

You will need to limit your cat's activity while it heals, setting aside a quiet place for it to rest, away from household activity, children, and other pets. You might consider cage rest for your cat, to limit its physical activity. Your veterinarian will tell you when it is safe for your cat to move about again. Most cats recover well from amputation, and learn to compensate for the lost limb.

It is important to monitor your cat's food and water intake while it is recovering. While your cat is in the process of healing, you may set the litter box up closer to where your cat rests, and make it so that it is easy to get in and out of the box.

Nerve tumors are usually locally invasive and do not metastasize. However, local recurrence is common after surgical resection and will need to be treated again.