Conjunctival Melanocytic Nevi With Granular Cell Change.

Context.—: Granular cell change in melanocytic nevus is underrepresented in the literature with only 4 well-documented cases, 1 described in the conjunctiva. Unfamiliarity with the clinical and pathologic features of these lesions contributes to the diagnostic difficulty.

Objective.—: To delineate the clinical and histopathologic features of conjunctival nevi with granular cell change.

Design.—: In a retrospective observational case series, the medical records of all patients with conjunctival nevi and granular cell change diagnosed between December 2016 and October 2018 were reviewed. Data collected included age, sex, clinical presentation, pathologic findings, and follow-up.

Results.—: Twelve patients, 6 males and 6 females, with a median age of 14 years (range, 8-82 years) were identified. The nevus manifested as a pigmented, well-circumscribed nodule (7 of 9; 78%) or patch (2 of 9; 22%) in the bulbar and limbal conjunctiva (7 of 9; 78%) or in the plica semilunaris/caruncle (2 of 9; 22%). Cysts were noted in 7 of 9 lesions (78%). Features prompting surgical excision included atypical pigmentation (8 of 9; 89%), growth (7 of 9; 78%), and atypical vascularity (4 of 9; 44%). Microscopically, all lesions comprised a conventional melanocytic nevus with focal granular cell change and immunoreactivity for Melan-A, SOX10, and HMB-45, with Ki-67 proliferative index of less than 2%. Of the 9 lesions with follow-up information, there were no recurrences over mean follow-up of 11.2 months (range, 1-23 months).

Conclusions.—: Granular cell change in melanocytic nevi is an underrecognized finding that can simulate melanoma clinically and histopathologically. Young age at diagnosis, lack of associated conjunctival melanosis, bulbar location, cysts, and the absence of mitotic figures with a low Ki-67 proliferative index are helpful clinical and pathologic diagnostic clues.