Eyelid Tumors in Cats

The eyelid is the most common location for a tumor in or around the eye in cats, and most are malignant. It is rare for an eyelid tumor on a cat to have a good prognosis, but early intervention is the best way to catch one before metastasis.

A mass on the eyelid is self-evident.

White cats with non-pigmented eyelid margins carry a high risk for developing squamous cell carcinoma of the eyelid. Eyelid tumors in cats usually have a poor prognosis, especially if cancer has metastasized.

As with all forms of cancer, both genetic and environmental factors are likely to impact risk.

Eyelid tumors are caused by different forms of cancers. Cancer is defined as abnormal, uncontrolled cell growth.

A mass on the eyelid is self-evident. It may have the following characteristics:

• Irregular shape and color
• Inflammation around the area
• May look like a sore at first

A number of tests are run to determine the type of tumor present:

• Physical examination
• Cytology of the tumor (cellular analysis under a microscope)
• Biopsy of the tumor
• Diagnostic imaging
• Bloodwork to evaluate overall health status

Treatment depends on the type of tumor.

Benign tumors that are not irritating the eye may be left in place. They may also be surgically removed, but large tumors may require extensive surgical reconstruction of the eyelid.

Malignant tumors are surgically removed, sometimes requiring the removal of an otherwise healthy eye to prevent metastasis. Small and contained tumors, especially SCC and mast cell tumors, can show a positive response to cryotherapy treatments. Lymphosarcoma tumors are often a sign of metastasis from a primary tumor and therefore are more responsive to chemotherapy and radiation.

If diagnostic imaging shows that metastasis has begun, cancer is often too developed to effectively respond to treatment. Care at this point will be focused on palliative treatment including pain management and stress reduction, and euthanasia is a possible outcome.

Malignant eyelid tumors have a higher risk of recurrence compared to benign tumors. This is generally seen within the first 6 months following treatment and remission.

Prognosis for eyelid tumors is best when the tumor is caught early and intervention begins before metastasis or increase in the size of the tumor.

Eyelid tumors cannot be prevented but some risk can be reduced by avoiding excessive UV exposure. Prognosis is best when detected early, so regular monitoring of changes to the cat’s eyelid can allow for earlier detection and a better chance for a good outcome. Eyelid tumors are not contagious.

Eyelid tumors in cats are the most common type of tumor in the eye area.

• Benign neglect
• Surgery
• Radiation
• Chemotherapy
• Palliative care