When it comes to conjunctival pigmented lesions, knowing how to manage nevus, primary acquired melanosis (PAM), and melanoma can dramatically help to improve patient survival, said Carol L. Shields, MD. Conjunctival melanoma is relatively rare, at about 0.43 per million persons,1 and this tumor can be fatal.
Conjunctival nevus tends to be pigmented and asymptomatic with a low risk for transformation into melanoma, somewhere under 1%, said Dr. Shields, co-director, Oncology Service, Wills Eye Hospital, and professor of ophthalmology at Thomas Jefferson University in Philadelphia. PAM tends to occur in Caucasians, is nearly always unilateral, and carries a chance for melanoma somewhere between 10% and 30%.
“We like to clean that up—we don’t want to see melanoma,” she said.
PAM is considered a strong precursor to conjunctival melanoma. Once a patient has a melanoma, there is a risk for invasion posteriorly in the orbit, with a 60% to 70% chance for metastasis, and ultimately, death from melanoma, Dr. Shields noted.