Excision of Tumor on Eyelid in Cats

Tumors on your cat’s eyelid are visible and usually noticed by pet owners. If caught early, they are usually treatable. Signs you may notice on your cat's eyelid are a red area, tearing or discharge, red eyes, blinking and squinting due to irritation of the eye surface by the tumor, or inflammation of the eyelid. Unfortunately, in cats eyelid tumor are often cancerous. However, the types of cancer found on the eyelid tend to be slow-growing and do not spread to other parts of the body quickly, so early treatment is critical and usually successful. Your veterinarian will need to determine if the growth on your cat's eyelid is a tumor or caused by another condition such as a fungal or bacterial infection. If a tumor is located, a biopsy will determine if it is cancerous. If cancerous tumors of the eyelid are present, treatment by a veterinary oncologist is recommended if available.

The most commonly seen eye tumors in cats are squamous cell carcinoma (SCC) tumors, with mast cell tumors (lymphosarcoma, mastocytoma) being the next most common eyelid tumors found in cats. Although slow growing, they can invade surrounding tissue and early treatment by a veterinarian is critical to secure a favorable outcome.

The tumor will affect your cat's vision and cause irritation to the eye’s surface and must be removed, even if not cancerous.

The extent of surgery required and the surgical procedure used to excise the eyelid tumor depends on the nature of the tumor and the extent of tissue affected.

If cancer is suspected, a biopsy of tissue will be performed by fine needle aspiration or tissue biopsy. The tissue will be analyzed to determine the type of cancer present.

Tests such as radiographs, blood, and urine tests will be performed to:

• Look for indications of cancer spreading
• Rule out other conditions causing lesions of the eyelid, such as fungal and bacterial conditions
• Determine basic health of your cat prior to anesthesia being administered
• Look for signs of feline leukemia virus or feline immunodeficiency virus, which may be contributing factors to lesions on the eyelid. If these viruses are present, treatment for those conditions will need to be considered as well.

Depending on the type and extent of the tumor, either cryosurgery or traditional surgery will be performed. 

Anesthesia will be required for either traditional surgery or cryosurgery on the eyelid. Your cat may be given a sedative to calm them prior to anesthesia being administered. If cryosurgery is being performed, which will be of shorter duration, intravenous anesthesia may be adequate. If a longer traditional surgery is required, intravenous anesthesia followed by the insertion of a breathing tube and maintenance of anesthesia with gas inhalation will be required.

Cryosurgery

This surgery is performed on small, contained tumors of the eyelid.

Freezing of unwanted tissue will be performed using a spray, probe, or manual application of liquid nitrogen using a swab. Another method of cryosurgery involves argon gas being used with a very thin (17 gauge) needle. The freezing usually takes about 30 seconds and if the tumor is cancerous, the tumor and surrounding tissue will be frozen to destroy it. There is no need for sutures, however the treatment may need to be repeated several times over a period of a few weeks.

Surgical Removal

Tumors that are too large or invasive for cryosurgery to be effective will be excised by traditional surgery methods.

This will involve removing the tumor and surrounding tissue with a scalpel and suturing the remaining tissue back together. Reconstructive surgery may be required, depending on the extent of tissue affected. In some cases, complete removal of the eye is necessary, when a cancerous tumor has sufficiently invaded surrounding optical tissue to warrant a more drastic procedure. In these case, the entire eye structure, including cornea, globe and optic nerve, will be removed surgically. Skin on the face and forehead will be sutured together to close the wound.

Excision of cancerous tissue may be accompanied by radiation therapy to ensure complete removal of cancerous tissue. 

If eyelid tumors are caught early, excision is usually effective at resolving the condition. The outcome for cancerous tumors that have become established is less successful. Complete removal of eyelid tumors is required and may require multiple treatments, especially if cryosurgery is the method of excision, to prevent them from growing back again. Excision of cancerous tumors in conjunction with other therapies such as radiation, chemotherapy (for leiomyosarcomas), or corticosteroids (for mast cell tumors) may be more effective.

After surgery to remove an eyelid tumor, your veterinarian will provide you instructions on aftercare and medications required. You will need to wipe any discharge away gently with a warm, clean, moist cloth. 

Do not allow your cat to rub, or scratch its eye. An Elizabethan collar may be of use to help prevent physical interference with the treated eye.

Monitor your pet's incision for signs of infection, loss of sutures, or signs of wound opening. If cryosurgery was performed, the wound may look infected even when it is not. If you are unsure, consult your veterinarian. If infection is present, antibiotics will be prescribed. Lubricated eye drops are usually given to lubricate the eyelid the surgery was performed on and prevent it irritating the surface of your cats eye. Anti-inflammatories and painkillers may also be prescribed.

Cats usually recover well from eyelid surgery and if caught early, recovery should be complete. If an eye needs to be removed, most cats will adjust to this with little complication.

Cryosurgery is more cost-effective than traditional surgery for the excision of eyelid tumors. However, cryosurgery of the eyelid will still involve anesthesia, making it more expensive than some cryosurgery procedures. Cryosurgery with anesthesia will usually cost in the $200.00 range. Cost of surgery to remove an eyelid tumor will vary depending on the extent of damage to the eye and surgical intervention required. If incision of the eyelid is straightforward and there is enough tissue to easily close surgery, it will be less expensive than if reconstructive surgery or complete removal of the eye is required. Traditional surgery to remove eyelid tumors can, therefore, range from $500 to $2,000 depending on the extent of surgery and cost of living in your area.

Most eyelid tumors in cats are cancerous, but slow spreading, requiring early attention by a veterinarian. If the tumor is not completely removed there is a chance it will grown back, requiring further treatment. As with any surgical procedure, there is a risk from anesthesia and a risk of infection but these can be mitigated with careful monitoring and antibiotics if necessary. If cancerous tumors of the eyelid are not removed they will metastasize to other tissues and eventually prove fatal. Non-cancerous tumors will interfere with your pet's vision and cause pain and discomfort in their eye due to irritation.

As most eyelid tumors in cats are caused by cancerous tumors, there may be little that can be done to prevent them. The cause of cancerous tumors in cats is not well understood, although there does appear to be a genetic predisposition towards certain types of cancers. Pale colored cats exposed to UV radiation (for example, white cats that are outside exposed to direct sun) may be at a higher risk for developing eyelid tumors. Keeping your cat indoors, or out of direct sunlight, can mitigate the development of these types of tumors.