Eyelid Margin Tumors

What is it?

The eyelids are an extension of the skin, so similar tumors can grow there. The edge of the eyelid has tiny meibomian glands that lubricate the eye; overgrowth of these cells causes benign meibomian gland adenomas or, less often, malignant adenocarcinomas. Pigment cells can form melanomas, and squamous cells can form squamous cell carcinoma, which is linked to sunlight, especially in light-coated or hairless breeds.

What signs should I watch for?

Benign growths often look like small polyps or cauliflower-like bumps on the inside or outside of the lid. Malignant tumors tend to look irregular or nodular and may ulcerate, bleed, or become infected and painful. Other signs include squinting, eye discharge, a protruding third eyelid, thickened conjunctiva, and pawing or rubbing at the eye. A growth that touches the cornea can cause painful scratches and ulcers.

How is it diagnosed and treated?

A fine needle sample may help, but often the growth is removed and examined by a pathologist (histopathology) for a definite diagnosis. If cancer is suspected, X-rays, bloodwork, and other tests may check for spread. Treatment is usually surgical removal, sometimes with freezing (cryotherapy) or radiation, and antibiotics or anti-inflammatories for secondary infection. Your veterinarian may refer you to a veterinary ophthalmologist.

Can it be prevented, and what's the outlook?

• There is no specific prevention, though limiting sun exposure may help light-coated dogs.
• Outlook depends on the tumor type and how early it is treated; prompt removal prevents eye damage and, for malignant tumors, reduces the chance of spread.