neurofibromatosis ( nf ) is an autosomal dominant disease , discovered in 1882 , by the german pathologist friedrich daniel von recklinghausen , characterized by disordered growth of ectodermal tissues , and is part of a group of disorders called phakomatoses ( neurocutaneous syndrome ) . neurofibromatosis type - i ( nf-1 ) , also known as von recklinghausen syndrome , is caused by the mutation of a gene on the long arm of chromosome 17 , which encodes a protein known as neurofibromin . it is characterized by spots of increased skin pigmentation ( caf au lait spots ) , combined with peripheral nerve tumors and a variety of other dysplastic abnormalities of the skin , nervous system , bones , endocrine organs , and blood vessels . the localized form of neurofibromatosis type - i , first described by gammel in 1931 , is very rare . crowe et al . proposed the term sectorial neurofibromatosis for this localized form of neurofibromatosis , and miller and sparkes modified the nomenclature to segmental neurofibromatosis ( sn )  the current term for neurofibromas of segmental distribution . the commonly affected sites for sn are the thorax and abdomen ( 55% ) , upper extremities ( 20% ) , and lower limb and face ( 10% each ) . only few cases ( less than 10 ) of segmental neurofibromatosis over the face have been described so far . a 26-year - old female patient reported to the dental department complaining about the unesthetic appearance of her face , since eight years [ figure 1 ] . history revealed that eight years back , the patient underwent surgery in the neck region for a cyst and one to two days after surgery the patient got a swelling on the face . the swelling was of the same size since then and there was no pain associated with the swelling . the unesthetic appearance of the face on examination , the face of the patient appeared asymmetrical , bilaterally , with a growth on the right side of the face . the skin over the right side of her face was thickened and hyperpigmented , with a soft and loose hanging overgrowth . there were numerous small and large , sessile and pedunculated nodular growths localized on the right side of her neck , with dark - colored underlying skin . the skin over the right cheek and chin area showed coffee - colored pigmentation ( caf - au - lait spots ) [ figure 2 ] . nodular growths localized on the right side of the neck with dark colored underlying skin there was a soft , compressible , nontender growth on the lower lip . the right ear showed disfigurement and hypertrophy , with thickened cartilage and overlying hyperpigmented skin [ figure 3 ] . disfigurement of the ear and hypertrophy with thickened cartilage and overlying hyperpigmented skin intraorally there were numerous soft tissue growths with a sessile base seen on the right buccal mucosa [ figure 4 ] and tongue [ figure 5 ] . soft tissue growths with sessile bases on right buccal mucosa soft tissue growths with sessile bases on the tongue laboratory findings revealed a raised erythrocyte sedimentation rate ( esr ) ( 70 mm in the first hour ) , a decreased hemoglobin level ( 7.5 gm% ) , and the enzyme - linked immunosorbent assay ( elisa ) was found to be nonreactive . a panoramic radiograph disclosed asymmetric enlargement of the right side of the mandible , with loss of cortication of the lower border in the midline area , expansion of the body of the mandible causing displacement of the teeth , seen on right side , expansion of the right inferior alveolar nerve canal , enlarged mental foramen , resorption of the roots of the mandibular right teeth , and loss of the right antegonial notch . a deficiency was seen on the right side of the maxilla , with crowding of the posterior teeth [ figure 6 ] . a panoramic radiograph the right lateral oblique radiograph revealed a deep sigmoid notch , loss of the antegonial notch , an enlarged and rounded coronoid process , with resorption of the mandibular right teeth [ figure 7 ] . a right lateral oblique radiograph subsequently , biopsy of one of the nodules was taken and sent for histopathological examination . the histopathological slide revealed a non - encapsulated tumor of the dermis with a normal overlying epidermis . the tumor consisted of loosely spaced spindle cells and wavy collagenous strands in a clear matrix [ figure 8 ] . a non - encapsulated tumor of the dermis , with a normal overlying epidermis these tumors are composed of schwann cells , fibroblasts , mast cells , and vascular components . the caf au lait spots are irregularly - shaped , evenly pigmented , brown macules . most individuals with neurofibromatosis have six or more spots that are 1.5 cm or greater in diameter . in young children , five or more caf au lait macules , greater than 0.5 cm in diameter , are suggestive of neurofibromatosis . less than 1% of the healthy children have three or more such spots , although one or two caf au lait macules are commonly encountered in healthy individuals without disease . bone involvement includes pseudoarthrosis of the tibia , bowing of the long bones , and orbital defects . treatment of neurofibromatosis is predominantly surgical . when neurofibromas increase in size or cause pain , malignant transformation must be suspected , and excision or biopsy must be performed . acoustic neuromas and tumors that cause tinnitus and vertigo must be excised with great caution . plastic surgeons may be included in the correction of deformities , especially those of the face . considering the autosomal dominant inheritance pattern of neurofibromatosis , genetic counseling
segmental neurofibromatosis is a rare disorder , characterized by neurofibromas or caf-au - lait macules limited to one region of the body . 
 its occurrence on the face is extremely rare and only few cases of segmental neurofibromatosis over the face have been described so far . 
 we present a case of segmental neurofibromatosis involving the buccal mucosa , tongue , cheek , ear , and neck on the right side of the face .