Squamous Cell Carcinoma in the Eye

An 87-year-old man sought treatment of an irritated, red left eye with an enlarging “growth.” Two years earlier, the growth in the eye had been examined by another ophthalmologist. The patient could not recall the diagnosis and stated that no specific therapy had been initiated.

An excisional biopsy of the lesion confirmed the suspected diagnosis of squamous cell carcinoma. Histopathologic evaluation showed more advanced conjunctival intra-epithelial neoplasia (carcinoma in situ).

Squamous cell neoplasia can occur as a localized, minimally aggressive lesion confined to the surface epithelium or as a more aggressive tumor that invades the under-lying stroma. The former has no potential to metastasize, whereas the latter can gain access to the conjunctival lymphatic channels and occasionally metastasize to regional lymph nodes.

The lesions often originate at the limbus, either nasally or temporally. They are most often seen in older, fair-skinned persons and occur more frequently in men.

A slightly elevated, fleshy translucent or gelatinous mass is revealed on slit lamp examination. Tufted blood vessels are usually prominent. Leukoplakia-a white plaque that occurs from secondary surface keratinization-is noted in about 10% of cases. Secondary inflammation often arises, which can lead to the misdiagnosis of atypical conjunctivitis.

In more advanced cases, as in this patient, the tumor can progress into the adjacent corneal epithelium and cause irritation, dryness, and vision distortion. Slit lamp examination reveals an advancing, gray, superficial opacity that may be relatively avascular or may have fine blood vessels. The full extent of the tumor can be further outlined by placing rose bengal dye in the eye. This dye stains degenerated and dead epithelial cells of the cornea and conjunctiva a red color, which highlights the involved tissue. The dye also can be used during surgery to help identify the margins of the lesion.

The tumor was completely removed under high-power magnification using a surgical microscope. The conjunctival part of the tumor can be excised with surgical scissors, while the corneal lesion is scraped off with a stainless steel blade; the corneal surface is then scrubbed with absolute alcohol to devitalize fragments of cells that may have crumbled during surgery.

Alternatively, the limbal area can be frozen with a cryoprobe in a double or triple freeze-thaw technique. Most recently, chemotherapy with topical mitomycin C and 5-fluorouracil has been used, particularly for recurrent or persistent disease. Recurrent lesions are often more widespread and raise concern about conversion to invasive squamous cell carcinoma. Eyes with lesions that involve more than 50% of the limbus and cornea may have a poor visual prognosis.

The patient was very pleased with the results of his surgery and was more comfortable after the corneal epithelial defect had healed.

However, the patient needs to be seen at least three times for follow-up during the first postoperative year and once every 6 months thereafter. There has been no recurrence of the cancer 9 months after tumor removal.