Association of conjunctival dysplasia (squamous intraepithelial neoplasia) with melanosis (microscopic non-proliferative melanin pigmentation)

Purpose: To determine the association between conjunctival epithelial dysplasia (squamous intraepithelial neoplasia) and its melanosis (microscopic non-proliferative melanin pigmentation) in conjunctival biopsies. Methods: In this retrospective case series, histopathological slides from all conjunctival biopsies obtained in Khalil Hospital affiliated with Shiraz University of Medical Sciences for a period of 6 years (April 2009–July 2015) were reviewed. After considering the exclusion criteria (non-melanotic pigmentation, melanocytic proliferations, and squamous cell carcinoma), conjunctival biopsies were divided histopathologically into two groups of dysplastic and non-dysplastic. Then, the slides were reviewed by one ophthalmopathologists and one general pathologist. Melanin pigmentation was recorded in both groups as 0, 1+, 2+, and 3+. The data were analyzed, and the groups were compared. Results: Overall, 685 cases with a mean age of 47.78 (±17.74) years were included in this study. Dysplastic and non-dysplastic groups comprised 135 (19.7%) and 550 (80.3%) specimens, respectively. Seventy-six percent (76%) of the specimens in the dysplastic group versus 40% in the non-dysplastic group had melanosis (P = 0.001). However, the degree of dysplasia (1+, 2+, and 3+) was not statistically correlated with the degree of melanosis (1+, 2+, and 3+) (P = 0.393). Conclusion: Our results demonstrated that melanosis is a common finding in conjunctival epithelial dysplasia and might indicate an association with conjunctival epithelial dysplasia.