Keratoacanthoma of the Eyelid

Keratoacanthoma of the Eyelid

A keratoacanthoma is a rapidly growing skin nodule that can appear on the eyelid over just a few weeks. It is dome- or cup-shaped, with a central plug of keratin (the hard protein of skin and nails) that gives it a volcano-like look. Its defining feature is also its danger: it grows fast and can then partly shrink on its own — but under the microscope it can be almost impossible to tell apart from an eyelid squamous cell carcinoma. For that reason it is taken seriously and removed for pathologic confirmation.

What It Looks Like

A keratoacanthoma classically presents as:

• A firm, dome- or cup-shaped nodule that appears and enlarges over weeks, not months or years
• A central crater filled with a keratin plug — the "volcano" appearance
• Skin-colored to pink or reddish, on sun-exposed skin such as the eyelid

The speed of growth is a key clue. Most benign eyelid lesions grow slowly or not at all; a nodule that visibly enlarges week to week deserves prompt evaluation.

Why It Cannot Simply Be Watched

Keratoacanthomas were once considered purely benign because some do involute (shrink) on their own. The problem is twofold. First, it can be clinically and even histologically indistinguishable from squamous cell carcinoma, a genuine eyelid cancer that can invade and spread if left. Second, even a "self-resolving" keratoacanthoma can leave a scarred, distorted eyelid in the process. Because the eyelid is small and functionally critical, the safe course is excision with pathology rather than waiting to see whether it shrinks.

Treatment

The standard of care is complete excision with pathologic confirmation. Removing the lesion does two things at once: it takes the growth off the eyelid, and it lets the pathologist examine the full specimen to confirm the diagnosis — noting that many pathologists now classify keratoacanthoma itself as a well-differentiated form of squamous cell carcinoma, which is a further reason it is treated surgically rather than observed. When cancer cannot be excluded on a partial sample, a full excision provides the definitive answer.

Because eyelid tissue is limited and every millimeter counts for lid function and closure, reconstruction after removal is part of the plan — an area where oculoplastic surgeons have specific reconstructive expertise. Where margins are a concern, excision may be coordinated with Mohs surgery for precise margin control, followed by eyelid reconstruction.

When to See a Specialist

Any eyelid nodule that grows noticeably over a few weeks — especially one with a central keratin crater — should be examined promptly. Do not wait for it to "go away on its own." An ASOPRS-trained oculoplastic surgeon can excise the lesion, confirm the diagnosis, and reconstruct the eyelid to preserve both appearance and function.