Differential diagnosis of the conjunctival melanoses.

The conjunctival melanoses are a group of diseases that share the common clinical findings of flat granular melanin-pigmentation of the conjunctival epithelium. Because differential diagnosis of these lesions is difficult, there is much confusion in the literature regarding taxonomy of these lesions. A histopathologic classification of benign melanosis; primary acquired melanosis with atypia, and primary acquired melanosis with melanoma is proposed. Benign melanosis should be divided based on clinical findings into complexion-associated melanosis, secondary melanosis, ephelis, and primary acquired melanosis without atypia.