Conjunctival Neoplasms

Two views of conjunctival neoplasm in squamous cell carcinoma.

Signs and symptoms: The primary conjunctival neoplasms seen in optometric practice include squamous cell carcinoma and, to a much lesser extent, malignant melanoma. With both these conditions, the typical patient tends to be older (50-plus) and white, often with a significant history of chronic sun exposure. Systemic immunocompromise may also predispose some patients to develop these neoplasms.

Squamous cell carcinoma of the conjunctiva often shows rapid onset and progression. In the early
stages, there may merely be a mild dysplasia, which often resembles a pinguecula, pterygium or even a phlyctenule. As the lesion grows, an elevated, fleshy mass of pink tissue develops in the interpalpebral space. Most often the lesion abuts the corneal limbus. These irregularly shaped neoplasms develop a rich intrinsic blood supply from the surrounding conjunctiva and episclera, with large-diameter "feeder vessels" emanating from the mass. Another hallmark sign is the presence of overlying "flaky" placoid white areas on the tumor surface, referred to as leukoplakia; this is a common finding in advanced or invasive conjunctival squamous cell carcinoma.

Conjunctival melanomas are relatively rare, accounting for fewer than 2% of all ocular malignancies. These lesions may present as a flat or nodular pigmented area, although amelanotic conjunctival melanomas have been documented. Like squamous cell carcinoma, they typically develop at the limbal margin. Vascularization is again readily evident, with numerous feeder vessels supplying the lesion. Unlike carcinomas, however, conjunctival melanomas tend to become multicentric if not diagnosed and managed promptly. Often, two or more focal neoplasms will "sprout" from a common feeder vessel, much like strawberries on a vine. Melanomas tend to progress more rapidly, and are more invasive into underlying ocular tissues. So, it is not uncommon to see associated uveitis or secondary glaucoma if the lesion invades the anterior chamber.

Conjunctival neoplasms may merely pose a cosmetic concern for patients in the early stages, and they may be noted on routine ocular examination. Larger lesions may interfere with lid function, causing dry eye complaints and possibly dellen formation on the adjacent cornea. Advanced, invasive lesions may compromise the episclera, sclera, cornea or angle structures. Pain may be a significant factor in later stages due to associated keratitis, uveitis or rise in intraocular pressure.

Pathophysiology: Neoplastic disorders can affect virtually all ocular tissues. Squamous cell carcinoma and melanoma of the conjunctiva represent primary malignancies of ectodermal tissue; they are forms of skin cancer. There are many risk factors for skin cancer, but for these lesions the most significant cause by far is chronic exposure to ultraviolet radiation. At the cellular level, these malignancies represent tissue that no longer responds to its genetic "program"; cells divide at an accelerated rate, invading and destroying surrounding tissue through compression and competition for blood supply. Malignancies lose the ability to carry out the normal metabolic functions of their tissue of origin, further compromising the organ system.

Management: Because the conjunctiva is only loosely adherent to underlying ocular tissues, the
prognosis for conjunctival neoplasms is generally very good. There is a relatively small risk of local extension into the eye and an even smaller risk of metastasis, provided the lesions are detected and treated early.

Biopsy is always indicated for unusual or suspicious lesions on the bulbar or palpebral conjunctiva. Biopsy-proven lesions call for surgical excision of the involved conjunctival tissue. The excision involves taking wide margins so that all of the visible tumor mass is removed. Typically, the surgeon then applies cryo- or laser therapy to the remaining borders to ensure complete destruction. In advanced cases in which the tumor extends into the surrounding tissues, enucleation or even exenteration of the orbit may be required to preserve the patient's life.

Alternative therapy for those who cannot or will not undergo surgery for these neoplasms includes chemotherapy or local radiation therapy. Chemotherapy does not enjoy a high success rate in cases of conjunctival neoplasm, and may induce a significant array of unpleasant side effects. Radiation of these lesions is also less successful than local excision, and poses great risk to surrounding ocular tissues at high doses. Corneal burns and radiation retinopathy are potential complications of this treatment.

Clinical Pearls:

• Suspect neoplasms with any rapidly growing mass on the conjunctival surface that fails to respond to antibiotic or anti-inflammatory therapies. Realize that two or more feeder vessels, leukoplakia, changes or variations in color or a predilection toward bleeding all constitute "red flags" for malignancy.
• When you suspect malignant melanoma of the conjunctiva, evert both the upper and lower lids to inspect for additional lesions of the palpebral conjunctiva. Likewise, always perform a dilated fundus examination and consider gonioscopy to rule out extension into the uvea.
• While most conjunctival neoplasms carry a good prognosis, metastasis is always a possibility; this is particularly true with melanoma, which can be extremely aggressive. Comanage patients with an experienced oncologist to be certain that the cancer has not spread to other organ systems. Because the liver is the single most common site of metastasis from ocular malignancies, testing liver enzymes is an important consideration for any patient with cancer of the eye.

Other reports in this section

• Conjunctival Neoplasms
• Allergic Conjunctivitis
• Vernal Conjunctivitis
• Acute Bacterial Conjunctivitis