Iris nevus showed a low risk of advancing to melanoma, according to a study, and a mnemonic guide can be used to remember factors that may predict growth.
The retrospective, comparative case series included 1,611 consecutive patients initially diagnosed with benign iris nevus who underwent observation and photographic documentation to evaluate potential advancement to melanoma.
Mean patient age at time of referral for iris nevus was 51 years.
Over a mean follow-up of 68 months, 27 eyes (2%) advanced to melanoma. Kaplan-Meier estimates of advancement to melanoma were less than 1% at 1 year, 3% at 5 years, 4% at 10 years, 8% at 15 years and 11% at 20 years.
Factors that predicted advancement to melanoma included age of 40 years or younger at presentation, an episode of hyphema, tumor in the 4 to 9 clock hour location, diffuse tumor involving the entire iris surface, ectropion uveae and feathery tumor margins.
Based on these results, the study authors said the mnemonic ABCDEF can be used to identify risk factors for growth: age young, blood, clock hour inferior, diffuse configuration, ectropion uveae and feathery tumor margins.