Conjunctival melanotic lesions in Chinese: comparison with Caucasian series

Conjunctival melanotic lesions in Chinese were studied and compared with those of Caucasians. These lesions were diagnosed in Chinese patients over a two-year period. They were excised under the clinical diagnoses of nevi, primary acquired melanosis (PAM) and malignant melanoma. For the cases included, the histology slides and clinical information were reviewed. Eighteen cases of nevi and nine non-nevoid lesions were identified. Among the non-nevoid lesions, there were eight cases of basal cell hyperpigmentation (one congenital, five acquired, two unknown) and one malignant melanoma. Benign or atypical melanocytic hyperplasias (MH) were not seen. This pattern is very different from that of Caucasian series. Acquired hyperpigmentation is almost only seen in Chinese and seldom in Caucasians. On the other hand, atypical MH is only seen in Caucasians, and not in Chinese. We conclude that conjunctival hyperpigmentation is associated with ethnicity and does not progress to MH, whether benign or atypical. It should be recognised as a distinct entity of no malignant potential that is part of the PAM clinical spectrum.