Iris cyst simulating melanoma.

Congenital cysts of the iris stroma are extremely uncommon and only a few cases have been reported. The vast majority of reported cases have been found in infants or children as a unilateral, translucent mass in the middle or peripheral third of the iris. 1-3 Although these cysts may remain dormant for years, they have a tendency to enlarge, causing corneal decompensation, secondary glaucoma, and eye pain. 2 Occasionally, they have been mistaken for iris melanomas leading to enucleation. 4,5 We describe a 14-year-old girl with a congenital cyst of the iris stroma, which over a period of 8 years enlarged, became opaque resembling melanoma, and required surgical excision.