Focal Blue Nevus of the Eyelid Margin (Mucocutaneous Junction): A Report of a Unique Case With a Review of the Literature

Purpose To describe the first isolated and focal benign blue nevus of the eyelid margin. Methods Review of clinical, histopathologic, and immunohistochemical characteristics and relevant literature. Results A 93-year-old Caucasian woman with a flat, irregular, and deeply pigmented black growth of the left upper eyelid margin of unknown duration underwent a full-thickness eyelid excisional biopsy. Microscopically, a population of loosely aggregated, mitotically inactive, heavily pigmented oval-to-elongated spindle dermal cells that paralleled the epithelium was seen. MART-1 and HMB-45 immunostaining of premelanosomes could not distinguish between melanocytes and melanophages. The more specific microphthalmia-associated transcription factor stained the nuclei of the subepithelial melanocytes before and after bleaching of the cytoplasmic melanin. The patient did not have Carney complex. No residual pigmentation or lesional recurrence has been noted during 6 months of follow up. Conclusions A blue nevus of the preorbicularis eyelid skin is extremely rare, and still more uncommon is such a lesion of the eyelid margin. Careful microscopic and immunohistochemical evaluation is necessary to establish the proper diagnosis. Wide local excision should be performed due to concern about a more common and serious melanomatous nodule. A differential diagnosis of other pigmented lesions in this location is offered.