plexiform neurofibroma is the term applied to a diffuse neurofibromatosis of nerve trunks , which is often associated with an overgrowth of the skin and subcutaneous tissues . it is a distinct type of neurofibroma that expands a nerve into a large tortuous mass of fibers that has a  bag of worms  appearance . plexiform neurofibromas are the least common variant and usually are pathognomonic for nf i. the most commonly involved sites are the temple , upper lid , back of the neck , and the tongue . oral manifestations of neurofibromatosis have been reported in only 4 - 7% affected persons , in which the tongue was the most commonly involved site . this systemic process , originally described by von recklinghausen , is an autosomal dominant disorder caused by a defect on chromosome 17 . patients usually present in childhood with numerous cutaneous or subcutaneous neurofibromas , melanotic lesions in the iris called lisch nodules , caf au lait spots , and optic gliomas . plexiform neurofibromas occur in only 17% of cases of nf i. when they occur in the setting of nf i , 91% are solitary lesions , and most of the lesions occur in the trunk , extremities , and head neck region . histologically , neurofibroma consist of endoneural ground substance and schwann cells that extend outside the perineurium . we present a case of an isolated plexiform neurofibroma of the tongue in a 11-year - old girl not associated with neurofibromatosis . an 11-year - old girl was admitted to the department of e.n.t . of our institute , with the complaint of inability to close the mouth because of a large , asymmetrical , protruding tongue . the girl had difficulty in swallowing , breathing , and clear speaking since early months of her life . on palpation , the right side of the tongue was hypertrophied and the movements of the tongue were normal , but she was unable to hold the tongue completely in the mouth because of its enormous size . there was also slight generalized swelling of the right side of the base of the tongue . no neck glands were palpable and functions of v , vii , x , and xii cranial nerves were intact . a magnetic resonance image was obtained to better assess the base of tongue , which revealed a 3  3  2.5 cm heterogeneously enhancing mass with infiltration in the tongue and tongue base , this lesion was hypervascular and well - circumscribed . under general anesthesia , gross examination of the specimen revealed irregular surface which was soft in consistency [ figure 1 ] . histopathological examination revealed well circumscribed multiple nodular lesions composed of elongated spindle wavy cells with muscle fibers in between , these wavy cells were arranged against a myxoid background . an ophthalmologic examination was carried out which showed no eye lesions of neurofibromatosis ( such as lisch nodules in the iris , ephelides on eyelids , or ectopia lentis ) . the skin of the whole body was examined and no caf au lait spots or frecklings of the axillary and inguinal region were observed . on plain radiograph , no bone pathology was found . after the diagnostic work - up , surgical treatment was planned . under general anesthesia , the tumor was approached intraorally , and the biopsy report was consistent with plexiform neurofibroma . the movements of the tongue were preserved , and , in addition , a significant improvement in her speech was observed . the patient has been on follow - up for 10 months and no additional treatment has been necessary . gross picture of neurofibroma h and e - stained section showing spindle wavy - shaped cells seperated by fibromyxoid stroma , 400 h and e - stained section showing discrete well - circumscribed collection of spindle cells with muscle fibers in between , 100 neurofibromas are benign tumors of neural origin , of which roughly 90% appear as solitary lesions . solitary plexiform neurofibromas arising outside the context of nf i , as illustrated in the patient presented here , are quite rare , with only scattered cases reported in the literature till date . in the literature , there are only few reports of macroglossia caused by plexiform neurofibroma , and the cases are almost always associated with neurofibromatosis . our patient had no eye lesion , no bone pathology , and no caf au lait spots or frecklings on the skin . we could not find any other signs or symptoms other than isolated plexiform neurofibroma of the tongue to make a diagnosis of neurofibromatosis , and thus it was concluded to be a case of isolated plexiform neurofibroma of the tongue . when these ill - defined tumors grow in the head and neck , they are commonly symptomatic and disfiguring , causing upper airway obstruction , swallowing or mastication difficulties , or cosmetic distortion of the face . diffuse plexiform neurofibroma , is also known as elephantiasis neurofibromatosa , which shows overgrowth of epidermal and subcutaneous tissue along with a wrinkled and pendulous appearance . neurofibromas of the large nerves , which appear clinically as soft , drooping , and doughy masses , are benign neoplasms composed of neurites , schwann 's cells and fibroblasts within a collagenous or myxoid matrix . in contrast to schwannomas , they are nonencapsulated and engulf the nerve of origin . plexiform neurofibromas , forming tortuous cords along the segments and branches of a nerve with a tendency to grow centripetally , are poorly circumscribed tumors . it needs to be differentiated from schwannoma which is encapsulated , while plexiform neurofibroma is noncapsulated ; moreover , in schwannoma there are antony a and antony b along with prescence of verocay bodies on microscopic examination . since neurofibromas are usually multiple lesions , the whole body must be examined and investigated . in patient with oral neurofibroma , larynx and trachea must also be examined as in such a case lesions in the upper airway may cause respiratory obstruction . plexiform neurofibromas should be monitored frequently because 5% may turn into malignant peripheral nerve sheath tumors . differential diagnosis of such a tongue mass must include neurofibroma , schwannoma ( neurilemoma ) , lymphangioma , hemangioma , hamartoma , teratoma , pyogenic granuloma , nerve sheath myxoma , and cystic lesions such as mucoid cysts and dermoid cysts . the standard treatment for neurofibromas has been surgical excision and the diagnosis can only be confirmed by histological examination . early diagnosis in such a patient is very important and these patients need regular follow - up during their lifetime to detect recurrences . fortunately , there were no signs of recurrence or other manifestations during the follow - up period of our patient till date . we present this case for its rare site along with nonassociation with neurofibromatosis , excellent recovery , and no recurrence till date on follow - up .
neurofibromas ( nf ) are benign tumors of neural origin , of which roughly 90% appear as solitary lesions . 
 they are classified into cutaneous , subcutaneous , and plexiform subtypes . 
 plexiform neurofibromas are the least common variant and usually are pathognomonic for nf i. here , we present a very rare case of isolated plexiform neurofibroma with a painless enlarging mass of the tongue of an 11-year - old girl . 
 this rare benign tumor has the potential for malignant transformation , and the diagnosis was difficult owing to the patient 's age and to the insidious clinical presentation . 
 the present case is a diffuse isolated plexiform neurofibroma of the tongue that was not associated with neurofibromatosis that was treated with intraoral surgery .