Bilateral segmental neurofibromatosis on the face.

Abstract

Dear Editor: Neurofibromatosis is a heterogeneous disorder clinically characterized by the presence of neurofibromas, multiple cafe-au-lait spots, intertriginous freckles, and Lisch nodules1. A 62-year-old woman presented with diffusely scattered papules on the forehead that had been present for 10 years. She had no family history of neurofibromatosis. On physical examination, asymptomatic, soft, flesh-colored papules of 3~5 mm diameter were observed to be distributed over the ophthalmic branch of the right and left trigeminal nerves (Fig. 1A, B). There were no other abnormalities in any other body region. Her general physical examination revealed a normal status, including intelligence, speech, auditory function, and visual acuity. Histopathological examination showed a well-circumscribed tumor in the dermis with a normal overlying epidermis. The tumor consisted of loosely spaced spindle-shaped cells and wavy collagenous strands in the myxoid stroma. Nuclear pleomorphism and mitoses were not observed (Fig. 1C). Overall, the features were consistent with a neurofibroma. The papules on the forehead were excised for cosmetic reason. Fig. 1 (A, B) Asymptomatic, multiple, soft, skin-colored papules on the right and left forehead. (C) Spindle-shaped cells and eosinophilic, thin wavy collagenous strands in the myxoid stroma (H&E, ×200). Segmental neurofibromatosis is a rare form of neurofibromatosis that is characterized by cafe-au-lait macules and neurofibromas, or only neurofibromas, distributed in only one dermatome, and less commonly in two or more dermatomes1. Segmental neurofibromatosis was categorized into four subtypes by Roth et al. in 1987: a true segmental form (type I), a localized form with deep involvement (type II), a hereditary segmental form (type III), and a bilateral segmental form (type IV). Our case belongs to the bilateral segmental type. Dermatologists should initially perform a physical examination to investigate for cutaneous manifestations elsewhere on the body and an ophthalmologic examination to detect Lisch nodules, in order to determine the presence of either generalized disease or segmental neurofibromatosis. No specific management guidelines exist for segmental neurofibromatosis; however, patients with the segmental type need to be assured that they do not have the generalized form of neurofibromatosis-1 and that they have a low risk of developing any disease-related complications2. Hager et al.1 reviewed 82 cases of segmental neurofibromatosis. The neurofibromas were mostly ulilateral; however, bilateral neurofibromas were reported in five patients. The affected dermatomes were the cervical (31 patients), thoracic (33 patients), lumbar (20 patients), and sacral (5 patients) dermatomes. To date, only nine cases of segmental neurofibromatosis on the face have been reported in the English literature3,4,5 (Table 1). To our best knowledge, this is probably the first reported case in the Korean literature of segmental neurofibromatosis involving the face. We report a case of bilateral segmental neurofibromatosis with an unusual location. Table 1 Review of cases of segmental neurofibromatosis involving the face reported in the English-language literature