Incidence of melanocytic lesions of the conjunctiva in a review of 10 675 ophthalmic specimens.

During the study period, 10,675 human ophthalmic specimens were received at The Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, McGill University, Montreal, Canada. Of those, 271 were conjunctival lesions (2.5%), with 101 being classified as melanocytic: 50 (49.5%) nevi, 36 (35.6%) primary acquired melanoses, and 15 (14.9%) melanomas. After exclusion of referred cases, 85 lesions were included in the study: 44 (51.7%) nevi, 33 (38.8%) primary acquired melanoses, and 8 (9.4%) melanomas. The most prevalent location was the bulbar conjunctiva. Conjunctival melanomas were most commonly found in an older age group than primary acquired melanosis or nevi. Conjunctival nevi were subdivided into compound (32.9%), subepithelial (16.4%), and junctional (2.3%). Primary acquired melanosis were further classified into primary acquired melanosis with atypia (8.2%) and primary acquired melanosis without atypia (30.5%). Primary acquired melanoses was the predisposing lesion in 75% of the cases of melanoma. In our sample, referral bias could alter the distribution of conjunctival pigmented lesions, with a shift toward the malignant end.