Scleral And Conjuctival Pigmentation

A 40-year-old white man came to see his physician about a brown spot in his eye . He noticed this spot many years ago, but after recently reading information on the Internet about brown spots in the eye, became concerned about ocular melanoma. He thinks the spot has changed in size. He denies any eye discomfort or visual changes. He was referred for a biopsy, and the pathology showed a benign nevus that did not require further treatment.

Case Discussion:

Scleral And Conjuctival Pigmentation:

Introduction: Scleral and conjunctival pigmentation is common and usually benign. Nevi can be observed and referred if they change in size. The etiology of scleral or conjunctival nevi is not well understood. Racial melanosis is genetically determined.

Clinical Features: depend on the cause of the pigmentation.
1. Physiologic melanosis is typically bilateral and symmetrical.
2. Primary acquired melanosis (PAM), Nevi, and melanoma are typically unilateral.
3. Intrinsic cysts are common in conjunctival nevi.

Diagnosis: Definitive diagnosis of pigmented ocular lesions is by biopsy.

• Eighty-seven percent of biopsy-proven nevi do not change over time.4
• Features seen more commonly in malignancy: ulceration, hemorrhage, change in color, and formation of new vessels around the lesion.
• Pathologic factors of conjunctival melanoma with a higher mortality rate include increased tumor thickness, location on the palpebral, caruncular or forniceal conjunctiva, increased mitotic activity, lymphocytic invasion, and association with PAM.

Differential Diagnosis:
Pigmented areas on the sclera or conjunctiva include the following:
• Benign nevi—Unilateral and stable over time .
• Physiologic or racial melanosis—Bilateral and symmetric, most common circumlimbally, and relatively consistent throughout patient’s life
• Primary acquired melanosis (PAM)—Typically unilateral, often multifocal indistinct areas of dark
pigmentation, and can progress to malignancy over time. This term is used clinically when the histology is not known.
• Secondary acquired melanosis—Seen with hormonal changes or after trauma to the conjunctiva with irradiation, chemical irritation, or chronic inflammation.
• Conjunctival melanoma—Unilateral, nodular, with variegated color and size changes
• Alkaptonuria—Rare disease accompanied by dark urine and arthritis.
• Nevus of Ota (also known as oculodermal melanocytosis)—Blue-gray scleral pigment involving the periorbital skin as well . It is more common in the Asian population but can be seen in any population. It can also be bilateral. Most importantly these persons should be followed by an ophthalmologist because they are at higher risk for glaucoma and possibly melanoma.

Management: depends on the underlying cause:
• Racial melanosis and nevi are two lesions that can be monitored for changes without a biopsy.
• Refer any changing pigmented lesion in the eye to a specialist who can perform a biopsy.
• Biopsy-proven PAM without atypia does not require excision, but must be monitored for stability.
• Melanosis with atypia is generally removed with large margins because of its potential for conversion into melanoma.
• The primary treatment for conjunctival melanoma is surgical removal. Cryotherapy, radiotherapy, and chemotherapy may be used as adjunct therapy.