A 40-year-old white man came to see his physician about a brown spot in his eye (Figure 16-1). He noticed this spot many years ago, but became concerned after recently reading information on the Internet 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.
Scleral nevus. Unilateral localized distinct area of dark pigmentation on sclera. (Reproduced with permission from Paul D. Comeau.)
Scleral and conjunctival pigmentation is common and usually benign. Nevi can be observed and referred if they change in size. Primary acquired melanosis (PAM) must be biopsied because PAM with atypia has malignant potential, whereas PAM without atypia does not. Conjunctival melanoma is rare, but deadly.
There is little information on the prevalence of ocular pigmentation other than complexion-associated melanosis (physiologic or racial melanosis).
In a study of pigmented lesions referred for biopsy, investigators reported that 52% were nevi, 21% were PAM, and 25% were melanoma.1
Scleral and conjunctival nevi (see Figures 16-1 and 16-2) are the most common cause of ocular pigmentation in light-skinned races. The pigmentation is generally noticeable by young adulthood and is more common in whites.2
Complexion-associated melanosis (Figure 16-3) is seen in 90% of black patients.3 It can be congenital and often presents early in life.
PAM (Figure 16-4) is generally noted in middle-aged to older adults4,5 and is also more common in whites.
Conjunctival melanoma (Figures 16-5, 16-6, 16-7) is rare; the incidence of conjunctival melanoma in Denmark was 0.5/1,000,000/year.6
Conjunctival nevus. Unilateral localized distinct area of pigmentation on the conjunctiva of a 17-year-old Hispanic female. (Reproduced with permission from Richard P. Usatine, MD.)
Complexion-associated (physiologic or racial) melanosis. Flat conjunctival pigmentation present bilaterally starting at the limbus and most prominent in the interpalpebral zone is likely to be racial melanosis in a darkly pigmented patient. (Reproduced with permission from Richard P. Usatine, MD.)
Primary acquired melanosis (PAM). Multiple unilateral indistinct areas of dark pigmentation. (Reproduced with permission from Paul D. Comeau.)
Conjunctival melanoma. Unilateral, nodular lesion with irregular contours and colors, and surrounded by hyperemic vessels. (Reproduced with permission from Paul D. Comeau.)