ABSTRACT
PURPOSE: Solitary plexiform neurofibroma of the eyelid without neurofibromatosis is a rare disease. We report a case of solitary plexiform pigmented neurofibroma of the eyelid without neurofibromatosis. CASE SUMMARY: A 12-year-old male visited our clinic with a painless palpable subcutaneous mass on the right lower eyelid. He had a history of Batter syndrome and attention deficit hyperactivity disorder. On initial presentation, clinical features regarding neurofibromatosis such as Lisch nodule, optic nerve glioma, or high myopia were not observed. We performed excision and biopsy of the lower lid mass under general anesthesia. Macroscopically, the tumor was 4.0 × 1.5 × 1.5 cm in size with irregular nodules. Microscopically, the tumor consisted of multiple, variably sized tortous enlarged nerve fascicles with clusters of pigmented cells. Immunohistochemical results revealed expression of S-100 protein. Pigmented cells express both S-100 and melan-A proteins, while nonpigmented cells express S-100 protein only. The tumor was finally diagnosed as plexiform pigmented neurofibroma. Dermatological evaluation revealed no evidence of systemic neurofibromatosis. CONCLUSIONS: Plexiform neurofibroma should be considered in the differential diagnosis of an eyelid mass, even if the patient does not have a history or clinical features of neurofibromatosis. Plexiform neurofibroma can be successfully managed with surgical excision.