Finding of conjunctival melanocytic pigmented lesions within pterygium

Aims: Conjunctival pigmented lesions have characteristic clinical and histopathological appearances. Melanocytic pigmented lesions commonly occur in the conjunctiva, although they have not been previously reported in pterygium, a common lesion which originates from conjunctiva. Our aim was to evaluate the possibility of an association between pterygium and conjunctival melanocytic pigmented lesions. Methods and results: A total of 80 samples of pterygium excised from Ecuadorian patients in 2002 were collected. Clinical data were available regarding age, sex, race and place of residence. Histological sections were evaluated for the presence of melanocytic pigmented lesions. Nine cases of conjunctival melanocytic, pigmented lesions within pterygium were found and were classified according to the histopathological criteria previously published for pigmented lesions of the conjunctiva, as naevi and primary acquired melanosis (PAM) with varying degrees of atypia. Five of the nine cases showed primary acquired melanosis without atypia, while two cases had atypia; one case showed features of compound naevus and one lesion was designated as subepithelial naevus. Conclusions: Our findings suggest that conjunctival melanocytic, pigmented lesions occasionally occur in pterygium. All surgically removed pterygia should undergo careful histopathological examination.