(BMJ)—A 46-yo Caucasian woman noticed a lesion in the white of her L eye increasing in size over a 6-yr period. Exam: wedge-shaped pigmented lesion, w/ dome-like thickening of the conjunctiva. No other lesions on full eye exam, w/ lid eversion. Retina WNL. What is the dx?
Primary acquired melanosis
Malignant melanoma
Benign conjunctival nevus
Conjunctival complexion-associated melanosis
Conjunctival foreign body
You are correct. Primary acquired melanosis was the clinical dx, based on appearance of this flat and noncircumscribed lesion. This condition is more likely to attract feeder vessels, as seen here, and typically occurs in white, middle-aged people. Confirmation of the dx, and determining whether it is benign or precancerous, requires histopathological eval. This pt opted to defer bx and instead be monitored by her ophthalmologist.

Nevi are often congenital or present from childhood. Malignant melanoma lesions are typically thickened, elevated, or nodular. Conjunctival complexion-associated melanosis is uncommon in white individuals.

BMJ 2020;368:l6810