Is a plexiform neurofibroma pathognomonic of neurofibromatosis type I?

Orbital and Lumbosacral Plexiform Neurofibroma with PTPN11 Mutation: A Form of the RASopathy

RASopathies are a group that encompasses a spectrum of related disorders caused by mutations linked to the RAS/mitogen-activated protein kinase (RAS/MAPK) pathway, including neurofibromatosis type 1 (NF1), Noonan syndrome (NS), neurofibromatosis-Noonan syndrome (NFNS), Noonan syndrome with multiple lentigines (NSML). Neurofibromas, as a hallmark of NF1, are extremely rare in patients with other RASopathies. Here we present a case of a 39-year-old Chinese male displaying orbital neurofibromas and lumbosacral plexiform neurofibromas. Histopathology of a CT-guided biopsy of the mass revealed it to be a neurofibroma. The targeted sequencing analysis did not find any pathogenic sequence alteration in the NF1 or NF2 causative genes in blood lymphocytes and hypertrophic nerve tissue, and no additional signs of NF1 were detected, thereby not meeting the diagnostic criteria for NF1. However, we identified a heterozygous mutation (c.836A>G, p.Y279C) in the PTPN11 gene, which is one of the key components of the RAS-MAPK signaling pathway and is associated with NS, NFNS, and NSML. Nonetheless, a thorough examination did not reveal any signs of these syndromes in the patient. Consequently, it was inferred that this patient likely falls within the spectrum of the RASopathies. This represents a unique case manifesting as orbital and lumbosacral plexiform neurofibromas carrying a PTPN11 gene mutation, thereby broadening the phenotype spectrum of PTPN11 mutations. Our results also highlight the overlap between RASopathies. Neurofibromas should be considered indicative of a broader spectrum of disorders resulting from mutations in RASopathies other than NF1.

Excision of Solitary Non-syndromic Oral Plexiform Neurofibroma Utilizing a Diode Laser: A Case Report

Plexiform neurofibroma is a benign peripheral nerve sheath tumor known to be pathognomonic for neurofibromatosis type 1. However, solitary plexiform neurofibroma in the oral cavity is extremely rare. Herein, we presented a 73-year-old Saudi male with solitary plexiform neurofibroma located on the maxillary alveolar ridge, which was excised successfully using a 940 nm diode laser. Microscopic examination revealed a multinodular arrangement of benign spindle cells in a haphazard pattern. Immunohistochemical analysis showed positive staining for S100 and CD34 in the tumor cells.

Deep-plane facelift technique for managing extensive hemifacial tumors: A retrospective study

This study aimed to evaluate functional and aesthetic outcomes in patients undergoing deep-plane facelifts for the management of extensive hemifacial tumors. The retrospective study included patients who had been diagnosed with benign tumors with extensive hemifacial involvement. All patients underwent tumor debulking via a dual-plane facelift approach, assisted by an ICG camera to visualize the facial nerve structures. To manage the laxity of the skin envelope, the deep-plane face-lift was performed by suspending the superficial musculoaponeurotic layer, followed by suture fixation to the parotid-masseteric fascia. Clinical outcomes, including complications, House-Brackmann grading for facial paralysis, and tumor recurrence rate were investigated. Quantitative facial nerve examination was carried out using FACE-gram software (Massachusetts Eye and Ear Infirmary, Boston, USA) to measure mouth corner movement at rest and when smiling. Using preoperative and 1-year postoperative 3D photographs, facial symmetry was assessed using comparisons of facial volume and the root-mean-square deviation (RMSD) value to represent the height difference between each hemiface. In total, 25 patients who met the inclusion criteria were recruited to the study. Regarding the types of tumor, 13 of the 25 patients were diagnosed with vascular lesions and the other 12 with neurofibromatosis plexiform. Following surgery, two patients showed temporary palsy of the buccal branches - grade II on the House-Brackmann scale - but neural functioning was eventually restored during the follow-up period. During resting, the mouth corner excursion ratio was significantly improved, from 1.11 ± 0.19 preoperatively to 1.02 ± 0.08 postoperatively (p = 0.022). The facial volume ratio was significantly improved in the lower face, from 1.57 ± 0.66 preoperatively to 1.19 ± 0.18 postoperatively (p = 0.008). The RMSD was significantly decreased, from 4.56 ± 2.35 mm preoperatively to 2.08 ± 0.99 mm postoperatively (p < 0.001), representing a decrease in facial asymmetry. Within the limitations of the study, it seems that the ICG camera-assisted deep-plane facelift technique allows preservation of facial nerve functioning and enhances facial symmetry when managing extensive hemifacial tumors.

Endoscopic Endonasal Surgery to Resect a Solitary Trigeminal Neurofibroma Involving the Infratemporal Fossa: A Case Report

Trigeminal neurofibromas are rarely reported, and even rarer when involving the infratemporal fossa. We describe the case of a 58-year-old man incidentally found through magnetic resonance imaging to have a tumor situated mainly in the infratemporal fossa. The tumor derived from the third branch of the trigeminal nerve and was totally removed by endoscopic endonasal surgery. Final pathology confirmed a diagnosis of neurofibroma. The patient had no intraoperative or postoperative complications except for numbness of the face. During the 6 years of follow-up, there has been no tumor progress or recurrence. We consider that endoscopic endonasal surgery is feasible in treating trigeminal neurofibromas involving the infratemporal fossa.

Plexiform neurofibroma with nevus of ota-rare presentation

Plexiform neurofibroma (PNF) is a rare form of neurofibromatosis type 1 which is rarely seen isolated. This generally spreads along the peripheral nerve and may affect some nervous rami. This is a poorly circumscribed and locally invasive tumor. About 21% of patients with NF-I are affected with PNFs. The nevus of Ota also called oculodermal melanocytosis is a macular discoloration of the face. It is most commonly found in the Japanese and very rare in the Indian subcontinent. It is unilateral oculodermal melanosis along the first two branches of the trigeminal nerve. We hereby present a very rare case of occurrence of isolated PNF (not associated with neurofibromatosis type 1) along with nevus of ota of the left side of the face in a 28-year-old female with thorough radiographic work up.

Mesenteric Plexiform Neurofibroma as a Cause of Weight Loss and Chronic Diarrhea in a Patient with YPEL3 Variant

Mesenteric plexiform neurofibroma is a subtype of plexiform neurofibroma that involves the mesentery and causes a variety of gastrointestinal complaints. Plexiform neurofibroma is classically found in patients with neurofibromatosis type 1, although genetic contributions to plexiform neurofibroma pathogenesis are heterogeneous. We report the first case of mesenteric plexiform neurofibroma in a patient with a YPEL3 pathogenic variant. This patient presented with growth failure, generalized abdominal pain and chronic diarrhea. She was confirmed to have mesenteric plexiform neurofibroma on histopathology and targeted sequencing on affected tissue confirmed that there were no neurofibromatosis type 1 variants present. Given that this patient's mesenteric plexiform neurofibroma is associated with YPEL3 dysfunction, she is unlikely to benefit from MEK inhibitors, which are the newly approved treatment for inoperable plexiform neurofibroma in patients with neurofibromatosis type 1.

Lumbosacral plexiform neurofibroma: a rare case in an adult without neurofibromatosis type I

Plexiform neurofibromas are an uncommon variant of neurofibromas that are described as being essentially pathognomonic of neurofibromatosis type 1 (NF1). Plexiform neurofibromas in the absence of NF1 are extremely rare. We present the case of a 38-year-old woman with a large multilobulated lumbosacral mass extending into the pelvis and proximal thigh. Histopathology of a CT-guided biopsy of the mass revealed it to be a neurofibroma. The imaging findings were consistent with a plexiform subtype. Further imaging and clinical workup showed that the patient had no other identifiable neurofibromas and did not meet criteria for the diagnosis of NF1.

Multiple spinal nerve enlargement and SOS1 mutation: Further evidence of overlap between neurofibromatosis type 1 and Noonan phenotype

Neurofibromatosis type 1 (NF1) has long been considered a well-defined, recognizable monogenic disorder, with neurofibromas constituting a pathognomonic sign. This dogma has been challenged by recent descriptions of patients with enlarged nerves or paraspinal tumors, suggesting that neurogenic tumors and hypertrophic neuropathy may be a complication of Noonan syndrome with multiple lentigines (NSML) or RASopathy phenotype. We describe a 15-year-old boy, whose mother previously received clinical diagnosis of NF1 due to presence of bilateral cervical and lumbar spinal lesions resembling plexiform neurofibromas and features suggestive of NS. NF1 molecular analysis was negative in the mother. The boy presented with Noonan features, multiple lentigines and pectus excavatum. Next-generation sequencing analysis of all RASopathy genes identified p.Ser548Arg missense mutation in SOS1 in the boy, confirmed in his mother. Brain and spinal magnetic resonance imaging scans were negative in the boy. No heart involvement or deafness was observed in proband or mother. This is the first report of a SOS1 mutation associated with hypertrophic neuropathy resembling plexiform neurofibromas, a rare complication in Noonan phenotypes with mutations in RASopathy genes. Our results highlight the overlap between RASopathies, suggesting that NF1 diagnostic criteria need rethinking. Genetic analysis of RASopathy genes should be considered when diagnosis is uncertain.

Multifocal Head and Neck Neurofibromas with Osseous Abnormalities and Muscular Hypoplasia in a Child with Neurofibromatosis: Type I

Neurofibromatosis type 1 (NF1) is a clinically and genetically distinct disease involving both neuroectodermal and mesenchymal derivatives. Orofacial manifestations in NF1 have been documented before but occurrence of multifocal intraosseous (IO) and extraosseous (EO) neurofibromas is rare. The present case highlights the importance of imaging findings in the diagnosis and management of multifocal jaw, infratemporal, and parotid neurofibromas with muscular hypoplasia in an eight-year-old girl with NF1. Apart from orthopantomograms (OPG), three-dimensional computed tomography (3D CT) and cross-sectional reformations were valuable in delineating the extent of the lytic lesion and identifying additional bony deformities of the mandible. Magnetic resonance imaging (MRI) helped to identify the solid nature of the lesion and true extent of the soft tissue mass.

Periodontal manifestations of von Recklinghausen neuro fibromatosis

Neurofibroma is an uncommon benign tumor of the oral cavity derived from the cells that constitute the nerve sheath neurofibromatosis type 1 (NF1), also known as von Recklinghausen's disease, is the most common type of neurofibromatosis and accounts for about 90% of all cases. It is one of the most frequent human genetic diseases, with the prevalence of one case in 3,000 births. Neurofibroma is seen either as a solitary lesion or as part of the generalized syndrome of neurofibromatosis. The solitary form does not differ from the disseminated form or the multiple form of the disease, except that systemic and hereditary factors present in the disseminated form are absent in the solitary type. Oral cavity involvement by a solitary and peripheral plexiform neurofibroma in patients with no other signs of neurofibromatosis is uncommon. The expressivity of NF1 is extremely variable, with manifestations ranging from mild lesions to several complications and functional impairment. Oral manifestations can be found in almost 72% of NF1 patients. This is a case report of a 40-year-old lady with a history of multiple faint rounded densities in the skin, chest pain occasionally since 8 months and breathlessness since 1 year and swelling of the right side of the angle of the mandible with limited mouth opening.

Diagnosis and management of an isolated pediatric plexiform neurofibroma involving the hepatic and celiac plexus using multimodality approach: problem solving with diffusion-weighted magnetic resonance imaging

Plexiform neurofibroma with involvement of the gastrointestinal tract is a very rare entity in children. Here, we present a rather unique case of a 9-year-old boy with no clinical signs or features of neurofibromatosis type 1. A periportal mass lesion was incidentally found after performing an ultrasound in this previously healthy child. Computed tomographic scan was subsequently performed which showed a low-density mass in a periportal distribution with extension along the celiac axis. Because the findings were nonspecific, a pre- and postcontrast magnetic resonance imaging of the abdomen was performed which included diffusion-weighted imaging. The lesion was then confirmed to be a plexiform neurofibroma with open biopsy. Management of plexiform neurofibromas varies widely. Given the extensive nature of the lesion, managing the patient with follow-up rather than surgical excision was favored.

Plexiform neurofibroma of the wrist: imaging features and when to suspect malignancy

Plexiform neurofibromas are essentially pathognomonic for neurofibromatosis type 1 (NF1), occurring when there is diffuse involvement along a nerve segment and its branches. Transformation into a malignant peripheral nerve sheath tumour (MPNST) is a major cause of mortality in NF1 patients. These tumours are highly aggressive and particularly difficult to diagnose in NF1 patients due to the clinical overlap between benign and malignant lesions. We present a case of a plexiform neurofibroma and discuss the typical imaging characteristics on ultrasound, CT, and MRI, including the target sign and continuity with the parent nerve. Certain imaging features should raise suspicion for malignancy however, these modalities may not always reliably differentiate between benign and malignant lesions. Recent studies show a very high negative predictive value for FDG-PET making it quite useful in excluding malignancy. In positive scans, PET/CT aids in guiding biopsy to the most metabolically active area of the tumour.

Oral hamartomas with von Recklinghausen disease

Neurofibromatosis is a genetically-inherited disorder of the nervous system that primarily affects the development and growth of neural (nerve) cell tissues and also causes cafe-au-lait spots on the skin, dysplastic abnormalities of the skin, nervous system, bones, endocrine organs and blood vessels. The two major classifications are NF-1, a generalized form, is the commonest and affects peripheral nerve tissues and NF-2, a rare central form, affects the central nervous system. An unusual finding of oral hamartomas may occur as part of NF-1 and here we presented one such rare case of oral hamartomas in a patient with Von-Recklinghausen's disease.

Neurofibroma in the left mandible: a case report

We report a rare case of isolated neurofibroma arising in the left mandible without family history of neurofibromatosis type 1. The tumor was histopathologically analyzed and an immunohistochemical panel comprising S-100 protein was performed. Vim, HMB45, and HHF35 were negative. The tumor cells were fusiform in shape, arranged in a plexiform manner, and grew actively. Features typical of neurofibroma, including an enlarged nerve fascicle composed of elongated nuclei and scant cytoplasmic cells, were identified. Our study suggest that neurofibroma can occur in the jaw as an isolated benign tumor in patients without other features of neurofibromatosis type 1.

Solitary oral plexiform neurofibroma: review of literature and report of a case

Plexiform neurofibroma (PN) is a rare, benign tumor of nerve sheath origin, which frequently manifests as part of neurofibromatosis type 1. The article presents a case of solitary PN in a 4-year-old girl, which manifested as a double lip and without systemic or familial involvement. A review of the literature on solitary PN in the oral soft tissue demonstrates the scarcity of such cases.

Plexiform neurofibroma of the submandibular gland in patient with von Recklinghausen's disease

Plexiform neurofibroma of the submandibular gland is an extremely rare tumor. Herein, we report a case of plexiform neurofibroma in a patient with a von Recklinghausen's disease (NF-1) who presented with a submandibular mass mimicking a submandibular gland tumor. Complete surgical excision provides the best treatment and final diagnosis. A neurofibroma should be considered in the differential diagnosis for submandibular mass.

[Isolated late-onset plexiform neurofibroma in the absence of neurofibromatosis]

BACKGROUND

Plexiform neurofibroma (NFP) is a benign nervous tumour typically involving the head and neck region due to the rich innervation of the latter. It is considered pathognomonic of neurofibromatosis type 1(NF1). This report describes an unusual case of neurofibroma and discusses its singular presentation, namely an isolated cutaneous tumour of late onset and with myofibroblastic histology.

CASE REPORT

A 85-year-old man presented swelling of the cutaneous part of the lower palpebral region which had been present for several months. The lesion was relapsing after repeated incomplete excisions and had grown slowly to become firm and suspect. It was decided to perform a large excision with a frontal rotation flap. Initial histological examinations performed on each excision suggested fibrosis and scarring, leading to diagnosis of fibrocytic change and post-surgical neuroma. The final histological analysis indicated diffuse plexiform neurofibroma with a myofibroblastic component. This was a solitary lesion in a patient without any stigmata or familial history of NF1.

DISCUSSION

This case is original in terms of its characteristics: a single cutaneous tumour of late onset in a patient with no stigmata of NF1 (in most cases of plexiform neurofibroma, NF1 is either multiple or else isolated at a mucous site). The histological findings for this tumour with a myofibroblastic component have never previously been described. Plexiform neurofibroma classically involves the head-and-neck region as in our case, with deep invasion of subcutaneous tissues making excision difficult and leading to frequent recurrence.

[Neural jaw tumors]

Neural tumors occurring in the jaw are neurofibroma and schwannoma, and more rarely ganglioneuroma. Pterionic meningioma are extremely rare. Schwannoma, or neurinoma are formed along the cranial nerve pathway, exclusively from axonal sheath Schwann cells. Neurofibroma are due to the proliferation of several cell types. When identified, screening for type I neurofibromatosis is mandatory. Surgery is the only treatment for facial neural tumors. Functional and esthetic issues are common. Recurrence and malignant transformation are severe complications of neurofibroma.

Neurofibromatous sensory neuropathy of the thigh in a 7-year-old boy

Neuropathy is considered to be an unusual complication of neurofibromatosis 1 (NF1). Neurofibromatous neuropathy is extremely rare in the setting of paediatric age group, pure sensory mononeuropathy and NF1. The following is a description of a 7-year-old boy who presented with complains of discomfort and parasthesia on the anterior aspect of his left thigh which is an unusual mode of presentation and site of involvement. Clinical examination and imaging revealed an isolated sensory neuropathy of the left anterior femoral cutaneous nerve of the thigh secondary to plexiform neurofibromatosis involving the L1-L4 nerve roots and the anterior femoral cutaneous nerve of thigh. The main abnormality in this patient was segmental hypertrophy of the left lower limb and dilatation of left lumbar neural foramens. Subtotal excision of the neurofibromas of the anterior femoral cutaneous nerve was performed and the patient was asymptomatic at the end of 27 months (2.25 years) of followup. Although the result of treatment in this case was good, long-term followup is necessary in view of greater risk of malignant transformation and development of spinal deformity and overall long-term poor prognosis in this particular patient subgroup of NF1.

Intra-parotid facial nerve multiple plexiform neurofibroma in patient with NF1

INTRODUCTION

Primary neurogenic tumours of facial nerve are uncommon with the majority found intra-temporally. Intracranial and intra-parotid neoplastic involvement of cranial nerve VII is much less common. There are 11 reported cases, in the English-language literature, of intra-parotid facial nerve plexiform neurofibromas with eight of them associated with NF1.

MATERIALS AND METHODS

A child, 10 years old, with NF1, reached us for a cheek swelling, slowly increased in previous 8 years. At the age of 3 years, a plexiform neurofibroma was diagnosed by biopsy of the lesion. Clinical examination and NMR showed in the sub-cutaneous tissue of the right cheek, two contiguous nodular lesions, about 2 cm x 1.5 cm in diameter; a third neoformed lesion, about 1cm in diameter, was located above the ipsilateral labial commissure. No facial nerve impairment was seen. The patient underwent superficial parotidectomy with removal of the lesions and preservation of the facial nerve.

RESULTS

The patient had a considerable regional swelling in the immediate post-operative course; no facial nerve impairment was observed. The swelling of the cheek did not show a fully regression in the post-operative course. Ultrasonography at 3 months showed a recurrence of disease.

DISCUSSION

Plexiform neurofibromas should be distinguished due to their risk of malignant transformation seen in up to 15% of patients affected by NF1. Surgery is the only effective option currently available for the treatment of PNF. However, success of surgical intervention is limited by the infiltrating nature of the tumours, resulting in a high rate of tumour re-growth. Facial nerve preservation during surgery is unlikely and significant morbidity can result from their excision. The age of the patient at surgical resection seemed to influence outcome: tumours resected before age 10 years recurred in 60% of cases compared with only 30% recurrence in patients older than the age of 10 years.

CONCLUSION

Indication and timing of surgery, in paediatrics patients with NF1, are complex. To avoid eventual physical and psychological consequences, it seems prudent to delay surgery as long as it is feasible for otherwise asymptomatic paediatric patients with facial plexiform neurofibroma.

A case of isolated giant plexiform neurofibroma involving all branches of the common peroneal nerve

Plexiform neurofibroma is generally considered as a component of neurofibromatosis 1, and a great majority of the cases with plexiform neurofibroma display other symptoms related to neurofibromatosis. Plexiform neurofibromas occur frequently in the head and neck region due to the rich innervation of the area, however appear rarely in the extremities. We report here an isolated giant plexiform neurofibroma involving the common peroneal nerve branches without symptoms related to neurofibromatosis in a 5-year-old case. Surgical excision was performed due to pain and numbness in the leg, and against the possibility of malignant transformation due to sudden growth observed in the tumor. One month following the excision of all the reachable tumoral tissues, tendon transfer surgery was performed for the ankle and toe extensions. Our case stands as the only reported case of isolated giant plexiform neurofibroma involving the common peroneal nerve in the pediatric age.

Neurofibromatosis 1 and neurofibromatosis 2: a twenty first century perspective

Historically, neurofibromatosis 1 (NF1) has been inextricably linked with neurofibromatosis 2 (NF2). Both are inherited autosomal-dominant neurocutaneous disorders that have high de novo mutation rates and carry a high risk of tumour formation. However, they are clinically and genetically distinct diseases and should be considered as seperate entities. NF1 is a common disease that mainly affects the skin and peripheral nervous system and causes characteristic bony dysplasia. By contrast, NF2 is a rare disorder with a relative paucity of skin manifestations and high-grade malignancy is unusual. Neurological symptoms are the predominant problem and the cardinal sign is bilateral vestibular schwannomas. In this Review, I discuss the pertinent diagnostic, clinical, and genetic symptoms of NF1 and NF2. I also examine the current views on the pathogenesis of these neurocutaneous disorders in the wake of advances in molecular genetics and the development of mouse models of disease.

Solitary plexiform neurofibroma(s): role of magnetic resonance imaging

A 10-year-old boy presented with a painless progressive swelling on the nape of the neck of 8 years' duration. When the child was 1 year old, the swelling appeared as a minute raised skin eruption the size of a pearl at the back of the neck. It was painless and progressive, continuing to increase in size until it reached the size of a walnut. At age 2 years, a minor surgical intervention was undertaken to remove the swelling, but a year later, it recurred at the same site. The size continued to increase until it reached the present size. Examination of the afflicted skin surface showed the presence of a globular, nonreducible swelling measuring 7.5 cm x 5 cm located on the upper posterior portion of the neck. Both the swelling and the skin over it were mobile and nontender. Otherwise, the boy's skin surface was without blemishes. On palpation, the swelling was plexiform, resembling a bag of worms. Magnetic resonance imaging (MRI) was performed on 1.5T MR (Signa, GE Healthcare, Chalfont St Giles, England) using T1 and T2 weighted fast spin echo and short tau inversion recovery sequences in the axial and sagittal planes. The images were marked by a well-defined, homogeneous signal intensity lesion in the subcutaneous plane of the nape of the neck. The lesion appeared isointense in T1W images and hyperintense in T2W images with few flow voids within the lesion. Based on the MRI findings, a diagnosis of superficial plexiform neurofibroma was considered. Results of routine liver and kidney function blood examination tests were within normal limits. Surgical resection was done under general anesthesia. As soon as the skin was excised, the swelling started bleeding profusely, but bleeding stopped almost immediately on the complete excision of the swelling. No cavities were present in the mass, and the underlying structures were normal. The wound was closed with nonabsorbable monofilament nylon suture. The postoperative period was uneventful. In addition to initial excision biopsy, all of the resected tissue material was subjected to serial sectioning for microscopic pathologic examination. Hematoxylin- and eosin-stained sections showed unremarkable epidermis with slight hyperkeratosis. Upper dermis showed circumscribed, lobular proliferation of spindle cells in a loose fibular background distorting much of the dermis and subcutaneous fat. Subcutis showed numerous thin-walled, ectatic blood vessels lined with prominent endothelium. Intervening tissue consisted of wavy bundles of collagen lined with elongated thin cells with tapering and wavy nuclei. The nuclear chromatin was bland without significant polymorphism or raised mitotic activity. A few nerve twigs were also seen within the tumor, which was infiltrating the surrounding fat.

Sporadic and multiple neurofibromas in the head and neck region: a retrospective study of 33 years

The neurofibroma occurs as isolated or multiple lesions frequently associated with neurofibromatosis type 1 (NF-1). The aim of this study was to analyze the clinical and histopathological features of neurofibromas, particularly the plexiform variant, in the skin and oral mucosa, discussing their pathogenesis as well as clinical management of isolated lesion unassociated with NF1. The clinicopathologic features of 66 neurofibromas in the head and neck region diagnosed at the pathology laboratories of the Bauru Dentistry School and Lauro de Souza Lima Research Institute from 1970 to 2003 were reviewed. The clinical data, therapy, and follow-up information were obtained from the medical records. The results showed a high frequency of cutaneous lesions (81.8%) occurring mainly in females older than 40 years. Isolated neurofibromas were found in 51.2% of patients, and multiple lesions were often associated with the NF-1. The histopathological analysis demonstrated that diffused neurofibromas occur more frequently than the plexiform type. However, one case of plexiform neurofibroma was detected in the oral mucosa as an isolated lesion non-associated with the NF-1. The indolent clinical behavior of isolated neurofibromas in the head and neck region and the absence of NF-1 association reinforce that sporadic lesion could be hyperplastic or hamartomatous rather than neoplastic in nature.

Neurofibroma of the Lingual Nerve: A Case Report

A neurofibroma of the lingual nerve is a rare clinical finding, the most common lesion site of a lingual neurofibroma being the tongue. In most situations, it is difficult to determine the precise nerve origins. Herein, we report a case of lingual nerve neurofibroma that presented as a submandibular mass, mimicking a submandibular gland tumor or solitary lymphadenopathy. Complete surgical excision of such a lesion for histopathologic examination provides a better treatment and final diagnosis. For a patient presenting with neurofibromatosis and a submandibular mass, a neurofibroma of nerve origin should be considered in the differential diagnosis.

Oral plexiform neurofibroma not associated with neurofibromatosis type I: case report

An unusual case of isolated plexiform neurofibroma arising in the oral cavity without other clinical manifestations or family history of neuro-fibromatosis-1 (NF-1) is described. The tumor was histopathologically analyzed and an immunohistochemical panel comprising S-100 protein, epithelial membrane antigen (EMA), collagen IV, and CD34 was performed. Typical features of plexiform neurofibroma characterized by enlarged nerve fascicles composed of elongated nuclei and scant cytoplasm cells were identified. Subjacent to the oral epithelium, tactile-like bodies were also detected. On the basis of this report, we would like to emphasize that plexiform neurofibroma can occur in the oral cavity as a benign isolated tumor in patients without other stigmata of NF-1.

Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant congenital dysplasia of the neural crest cells that affects the development of tissue and structures arising from the 3 germinal layers. Affected patients may present with spinal deformities or with bone or soft tissue abnormalities. Imaging plays an important role in the evaluation of these patients. In this article, a working diagnosis approach is proposed and the spectrum of spinal imaging findings in the NF1 patient is reviewed.