Pediatric zygomaxillary neurofibromatosis type 1: case report.

N eurofibromatosis type 1 (NF-1) is a genetic disorder predominantly affecting tissues derived from neural ectoderm producing a multifocal neurocutaneous disease. It is usually inherited as an autosomal dominant trait with variable penetrance and phenotypic expression, affecting one in 2500-3300 live births. A closely related condition, neurofibromatosis type-2 (NF-2) occurs much less frequently (approximately one in 50,000 births) and is manifested primarily as multiple neurilemomas and acoustic neuromas. The clinical diagnosis of NF-1 requires two or more of the following manifestations: 1. At least six cafe au lait clinical macules with diameters of at least 5 mm occurring in prepubertal individuals and diameters greater than 15 mm in postpuberal individuals 2. Two neurofibromas of any type or one plexiform neurofibroma 3. Freckling in the axillary or inguinal regions 4. Optic gliomas 5. At least two Lisch nodules (pigmented hamartomas of the iris) 6. A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex (with or without pseudoarthrosis) 7. A first-degree relative (parent, sibling, or offspring) with NF-1.The oral cavity is involved in as many as 92% of the cases reported. The tongue is affected most frequently, often demonstrating unilateral macroglossia with or without enlargement of the fungiform papillae (53%). The mandibular canal may be enlarged (29%) or branched (24%), or there may be widening of the mandibular foramen (34%).' The lips, palate, buccal mucosa, gingiva, and oral floor also can be affected, with the maxillary and mandibular alveoli involved less often. Plexiform neurofibromatosis also can occur, producing large neuromas of the lingual, glossopharyngeal, or even the vagus nerves.-Invasion of the trigeminal nerve can produce variable degrees of paresthesia or neuralgia. The formation of acoustic neuromas also can produce a variety of symptoms reflecting vestibulocochlear nerve involvement resulting in deafness or vertigo. The clinical course can be exacerbated by or precipitated during pregnancy. This is thought to occur because of undefined nerve growth factors present in amniotic fluid in high concentrations. Some individuals may experience accelerated growth of the lesions during adolescence, because B-estradiol appears to stimulate the production of nerve growth factor. However, a clinical diagnosis of NF-1 is possible in the vast majority of cases (>90%) at infancy or early childhood.