Solitary intraosseous neurofibroma of mandible.

Solitary intraosseous neurofibroma is a rare benign non-odontogenic tumor. Although neurofibromas occur predominantly as a feature of neurofibromatosis affecting the soft tissue, a few cases of solitary intraosseous neurofibromas of the jaw have been reported. We herewith report a case of solitary intraosseous neurofibroma of mandible in a middle-aged woman with a discussion on its clinical, radiological, and histopathological presentation along with review of cases.     

Subtotal and total resection of superficial plexiform neurofibromas of face and neck: four case reports.

INTRODUCTION: Plexiform neurofibromas are benign tumours of the peripheral nerves and connective tissue. They develop most often in patients with neurofibromatosis type 1 (NF1) and often grow continuously. Removal of plexiform neurofibromas is usually unsatisfactory because the network-like growth of these tumours often involves multiple nerve fascicles and other adjacent tissues. It has been previously shown that magnetic resonance tomography can distinguish the growth patterns of plexiform neurofibromas into three different categories: superficial, displacing and invasive. PATIENTS AND METHODS: Three cases are described with successful subtotal resections of superficial plexiform neurofibromas, and one case with total resection following the diagnosis of tumour subtype using magnetic resonance imaging (MRI). RESULTS: There was a significant, lasting improvement in appearance which demonstrates that surgical intervention in the case of superficial plexiform neurofibroma is valuable. CONCLUSION: Careful classification of plexiform neurofibroma by means of MRI provides valuable information for the surgical management of patients. It enables the distinction to be drawn between this subtype and the other two subtypes of plexiform neurofibromas.     

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.     

Solitary intraosseous neurofibroma of the mandible. Apropos of a case

Neurofibroma is a benign neoplasm derived from peripheral nerves. Most of these are associated with Neurofibromatosis but may also occur as solitary lesions. When found on the head and neck they are generally located in the soft tissue. Intraosseous location is very rare. The following report describes a case of an intraosseous neurofibroma located in the left mandibular ramus of a 14-year-old child. The patient did not had clinical evidence of the lesion and it was found on a routine radiographic examination. Surgical excision of the lesion was scheduled and the sample was submitted to histopathological study. Representative sample cuts were studied using conventional techniques of hematoxylin-eosin and immunohistochemistry using primary antibodies anti S-100 protein, vimentin, and neuroespecific enolase. A review of clinical, radiographic, histologic and immunohistochemical features of other cases of intraosseuos neurofibromas located in the jaws together with the possible differential diagnosis of the lesion are discussed. Our case corresponds to a intraosseous neurofibroma of controveltial diagnosis because even though it presents typical neurofibroma histomorphological features it has immunophenotype different from usual.     

NF1相关神经纤维瘤炎症微环境的研究进展

[提要]神经纤维瘤是I型神经纤维瘤病的特征性症状之一,终生进展,治疗难度大,而其发病机制仍不明确.瘤内的施万细胞呈NF1双等位基因失活状态,可激活RAS-GTP信号转导,继而释放大量细胞因子,为免疫细胞的募集提供了富含细胞因子的微环境.相较于免疫炎症细胞在正常外周神经中的低占比率,在NF1相关神经纤维瘤中,30％的细胞...     

Immunohistochemical study of GLUT-1 in oral peripheral nerve sheath tumors

Aim:  To investigate the immunoexpression and diagnostic applicability of human erythrocyte-type glucose transporter protein (GLUT-1) in oral peripheral nerve sheath tumors.
Material and methods:  Specimens diagnosed as oral peripheral nerve sheath tumors archived in the Oral Pathology Service of Universidade Federal de Minas Gerais from 1966 to 2006 were evaluated. Thirty-four lesions were included: 15 traumatic neuromas, 11 neurofibromas, four neurilemmomas, and four malignant peripheral nerve sheath tumors (MPNST). One case of neurofibroma was associated with neurofibromatosis type I. Immunohistochemistry for S-100 and GLUT-1 was performed. S-100 was immunopositive in all lesions.
Results:  Benign lesions were immunopositive for GLUT-1 except in two (18.2%) cases of neurofibromas. In the traumatic neuroma, the perineuriums were immunopositive for GLUT-1. In the neurofibroma, the immunoreactivity was heterogeneous. Immunopositivity was observed at levels of 54.5% in the periphery of the lesion, 9.1% in the center, and 18.2% in both. The neurilemmoma demonstrated immunopositivity in the capsule. One case (25%) of MPNST presented GLUT-1 positive stain in occasional cells distributed homogeneously in all the tumor area.
Conclusion:  GLUT-1 is a useful marker for perineurial cells and should be included in the oral peripheral nerve sheath tumors immunophenotyping thus aiding in the correct diagnosis of these lesions.     

Solitary neurofibroma of the temporal bone

Neurofibroma is a benign peripheral nerve sheath tumor that can be occasionally found in the head and neck region as multiple lesions associated with neurofibromatosis type 1 (NF-1) or as a solitary tumor. The real frequency of isolated neurofibromas not associated with NF is uncertain, and lesions in the temporal region are extremely rare. The aim of the current article was to report an unusual case of solitary neurofibroma localized in the temporal and infratemporal regions with 10 years of evolution in a female patient without any other manifestation or familiar history of NF-1. The patient underwent surgical treatment for complete excision of the lesion, and the 2-year follow-up revealed no signs of recurrence.     

Maxillofacial deformities in neurofibromatosis

Four patients with neurofibromatosis are described: all displayed the feature of an increased depth of the sigmoid notch probably due to an expansive growing neurofibroma of the inferior alveolar nerve. One patient had a local neurofibroma with an invasive growth pattern and only this patient shows hyperplasia of the bone. The suggestion is made, contrary to what is found in the literature, that only the invasive growth type gives rise to hyperplasia and this type is always concomitant with a localized form of neurofibromatosis.     

Gingival neurofibroma in a neurofibromatosis type 1 patient

Neurofibroma is a benign peripheral nerve sheath tumour. It is one of the most frequent tumours of neural origin and its presence is one of the clinical criteria for the diagnosis of type 1 neurofibromatosis (NF-I). Neurofibromatosis type 1 is an autosomal dominantly inherited disease due to an alteration in the long arm of chromosome 17. About 50% of NF-I patients have no family history of the disease. NF-I patients have skin lesions (cafe au lait spots and neurofibromas) as well as bone malformations and central nervous system tumours. Diagnosis is based on a series of clinical criteria. Gingival neurofibroma in NF-I is uncommon. Treatment of neurofibromas is surgical resection. The aim of this paper is to report a case of NF-I with gingival involvement and to review the literature.     

Fehlbildungen der Kieferhöhle bei Neurofibromatose Typ 1

Aim. The aim of this study was to determine the malformations of the maxillary sinus in neurofibromatosis type 1 patients (NF1). Material and Methods. Twenty-two patients with NF1 were investigated clinically and radiologically: 11 had an unilateral trigeminal plexiform neurofibroma and 11 had multiple cutaneous neurofibromas. The histological type of NF was ascertained in all cases following tumor resections. The malformation of the maxillary sinus was assessed on plain radiographs and computed or magnetic resonance tomograms. Intraindividual side comparison was used to judge the size of the sinus and its position in the midface. Results. In patients with cutaneous neurofibromas the maxillary sinus appeared symmetrical in size and position. The pneumatization of the sinus had no abnormalities on the radiographs. Malformations of the maxillary sinus were restricted to plexiform neurofibromas. On the side affected by a plexiform NF, the sinus appeared hypoplastic and caudally displaced due to an enlarged ipsilateral orbit. The expansion of the sinus to the lateral side was impaired, obviously due to tumor masses. Consecutively, the alveolar process of the affected side was also displaced leading to a complex malocclusion. Discussion. Malformations of the face are frequently presented as case reports in the literature. Emphasis is given to the elephantiasis-like tumor growth of the face in certain patients with NF1. The underlying pathology has not yet been fully understood. This report provides evidence that in the midfacial region the overgrowth is predominantly caused by the plexiform neurofibroma itself and that the bones can even be hypoplastic and show scoliosis-like malformation compared to the nonaffected side. These findings are relevant when debulking procedures of the face are planned for NF1 patients.     

Manifestations of the tongue in Neurofibromatosis type 1

OBJECTIVE: The aim of this study is to analyse alterations of the tongue and the correlation between these lesions and different types of tumor. SUBJECTS AND METHODS: A total of 258 cases (131 females, 127 males) of neurofibromatosis type 1 were screened between 1994 and 2004 in our Dermatology Department. All patients included in this study have NF1, as defined by the NIH Consensus Conference. Three cases of neurofibromas of the tongue in patients with neurofibromatosis type were reported. RESULTS: Our patients showed nodular lesions on the tongue, related to neurofibromas in two patients and plexiform neurofibroma in one patient, respectively. Clinical and hystopatological findings were useful in distinguishing between neurofibromas and other soft tissue tumors. An increased prevalence of malignancy has been documented in patients affected by neurofibromatosis type 1. Changes in the size of a pre-existing mass, compression, or infiltration of the adjacent structures indicate malignant degeneration. Histological and clinical evaluation should be performed in order to choose the most appropriate treatment strategy for these patients. CONCLUSION: The oral manifestations of NF are well-documented but may not be at the forefront of the clinician's mind in the differential diagnosis of intra-oral swellings.     

Myxoma of the jaws. An analysis of 15 cases

A retrospective study on 15 patients with myxomas of the jaws was carried out. The series consisted of 3 males and 12 females. The mean age was 26 years. The maxilla was involved in 4 cases whereas the tumour was situated in the mandible in 11 cases. Of the 9 patients who underwent conservative treatment, one exhibited recurrent tumour. Six patients were treated by resection including uninvolved adjacent tissue; none of them has so far exhibited recurrence. These results indicate that carefully performed conservative treatment for myxomas is justified in some instances. Histologically, myxomas of the jaw exhibit mitotic activity in the majority of cases which indicates a distinct proliferative activity. Myxomatous degeneration in neurofibromas may mimic myxoma. Therefore the present cases were compared with 2 cases of intramandibular neurofibroma. It is concluded that differences in nuclear morphology are sufficient to distinguish between both neoplasms.     

Oral soft tissue alterations in patients with neurofibromatosis

Our aim was to characterize the type and frequency of oral soft tissue alterations in neurofibromatosis. A total of 103 patients with neurofibromatosis 1 (NF1) and three patients with neurofibromatosis 2 (NF2) were clinically evaluated for their oral soft tissue alterations. Disturbing growths were removed from nine patients with NF1 and from one patient with NF2. The specimens were analyzed using routine histological methods and with immunohistochemistry using antibodies to S100, type IV collagen, CD34, neurofilament, and neuron-specific tubulin (TUBB3). Alterations including oral tumors, overgrowths of gingival soft tissue, and enlarged papillae of the tongue were discovered in 74% of NF1 patients. The results showed that three tumors clinically classified as plexiform neurofibromas and five out of six discrete mucosal tumors displayed histology and immunohistology consistent with that of neurofibroma. The histology of one palatal lesion resembled that of a scar, and the lesion removed from the patient with NF2 was classified as an amyloid tumor. To conclude, oral soft tissue growths are common findings in NF1, but most lesions do not require treatment and the patients may even not be aware of these alterations. Collagen IV, S100, and CD34 are useful biomarkers in the analysis of NF1-related oral soft tissue tumors. The clinicians should recognize that oral soft tissue alterations are relatively common in NF1. Some of the growths are disturbing, and plexiform neurofibromas may bear a risk of malignant transformation.     

A 38-year review of oral schwannomas and neurofibromas in a Brazilian population: clinical,histopathological and immunohistochemical study

The benign peripheral nerve sheath tumours are rare lesions mainly represented by schwannoma and neurofibroma. The present work evaluated the clinical and histopathological features of schwannomas and neurofibromas of the oral cavity diagnosed in a Brazilian population. Among 9.000 cases of oral lesions archived from 1970 to 2008, four schwannomas and 12 neurofibromas were identified, microscopically revised and immunohistochemically certified through a panel including monoclonal antibodies (anti-S100, vimentin, HHF-35 and desmin). From biopsy and histological sections records, clinical and histopathological data were retrieved, reviewed and statistically analysed. Predominantly, schwannomas affected non-white males (3:1), with an age and size averages of 34.7 years and 2.8 cm, respectively. Neurofibromas preferentially occurred on the gingival/alveolar ridge of white females (5:1), with 35.7-year mean age, peak of incidence between 3rd and 5th decade, and size average of 1.7 cm. (12 cases, 75%). The studied tumours exhibited more frequently as a painless, sessile and slow growth very similar to other oral lesions, but their microscopic features differed significantly. Schwannomas and neurofibromas are extremely uncommon in the oral cavity, exhibiting clinical features very similar but specific and peculiar microscopic findings that are useful in the establishment of the diagnosis, which in some particular cases must be confirmed by immunohistochemistry.     

手术结合平阳霉素注射治疗巨舌症1例报告

巨舌症是指由舌组织增生和水肿引起的舌体过度肿大,可由各种不同原因引起,如血管瘤及淋巴管畸形、神经纤维瘤、甲状腺功能低下、血管神经性水肿、淀粉样变及其他疾病等。其临床治疗困难,本文报告采用手术加平阳霉素局部注射成功治疗淋巴管静脉畸形导致的巨舌症的临床经验,并结合文献,对其临床症状及治疗方案进行讨论。     

Multicenter study of wound healing in neurofibromatosis and neurofibroma

Based on clinical experience, the senior author has become convinced that wounds produced to correct the deformities of patients with neurofibromatosis (NF-1) have produced remarkably good scars, the interesting feature being that progression to keloid or hypertrophic scar is rare. The other point noted was that this situation did not change, no matter the patient's race or skin color. There have been few reports describing or discussing this hypothesis. The purpose of this study was to investigate whether wounds produced in the patients with NF-1 produce keloid or hypertrophic scars. The patients with solitary neurofibroma were also included in this study; these were compared with the NF-1 group. This was conducted as a multicenter study. Patients with neurofibromatosis/solitary neurofibroma, who were operated on from 1990 to 2000, were evaluated by reviewing their medical charts and photographs retrospectively. The patients were treated in centers from five different countries. The analysis was undertaken based on the following points: 1) age and sex at surgery; 2) race of the patients; 3) past and family histories of hypertrophic scar and keloid; 4) surgical site(s); 5) diagnosis, NF1 or solitary neurofibroma; 6) surgical complications; 7) number of reoperations to manage the complications; 8) adjuvant therapy for the tumor; 9) depth of the tumors; and 10) incidence of malignant degeneration. A total of 101 cases with neurofibromatosis or solitary neurofibroma was analyzed. The age at surgery ranged from 1 year 6 months to 74 years; sex ratio was 47 males and 54 females. The racial distribution of the patients was 13 white, 13 black, 3 Hispanic, and 58 Asian. There was no past or family history of hypertrophic scar or keloid. The surgical sites were head and neck in 70 cases, trunk in 20 cases, upper extremities in 22 cases, and lower extremities in 20 cases. The clinical diagnosis was NF-1 in 57 cases, solitary neurofibroma in 35 cases, plexiform neurofibroma in four cases, and no distinct clinical diagnosis in five cases. There were no other types of neurofibromatosis. Hematoma and white wide scar were the main postoperative complications found in six cases of NF-1. Infection was also noted in four cases. However, no patient developed hypertrophic scar or keloid in the neurofibromatosis group, whereas two cases showed hypertrophic scar in the solitary neurofibroma group. The outcome showed that the patients with NF-1 and plexiform neurofibroma, no matter the racial group, produce good scars without keloid or hypertrophic changes, whereas solitary neurofibroma has a potential to cause hypertrophic scar.     

下颌骨神经纤维瘤的临床及病理特点：1例报告及文献复习

目的：分析总结下颌骨神经纤维瘤的临床及病理特点。方法：分析1例左下颌骨神经纤维瘤患者的临床资料,并检索和回顾分析相关中英文文献。结果：收集文献33篇,英文26篇,中文7篇,均为临床资料完整的个案报道,共计39例。结论：下颌骨神经纤维瘤是一种罕见的良性肿瘤,女性多见,缺乏特异性的临床表现,确诊依据病理和免疫组化。该肿瘤缺乏包膜,有一定的侵袭性,易复发,恶变少见,预后较好。     

Neurofibromatosis type 1: a clinicopathological study of the orofacial manifestations in 6 pediatric patients

Neurofibromatosis type 1 (NF1) is a relatively frequent mucocutaneous syndrome, which is transmitted as an autosomal dominant trait or which may represent neomutation. It is characterized by a variety of clinical manifestations, including multiple neurofibromas that are associated with a high risk of sarcomatous transformation. The aim of this report was to elucidate the orofacial manifestations observed in 6 pediatric patients (between 4 and 15 years of age) diagnosed with NF1. Physical, clinical, radiological, histological, and immunohistochemical studies were performed. Orofacial lesions were observed in all studied patients, located either in the soft tissues (4 cases) or centrally in the jaws (2 cases). All cases showed facial asymmetry, one of them exhibiting marked facial hemihypertrophy. All cases with soft tissue involvement were plexiform neurofibromas, while the intraosseous cases were diagnosed as solitary neurofibromas. Knowledge of the variability of presentation of orofacial soft tissue and bone manifestations of NF1 in children is necessary for prompt diagnosis.     

Single-stage total and near-total resection of massive pediatric head and neck neurofibromas

Plexiform neurofibromas traditionally have posed a surgical challenge in pediatric patients. Expert preoperative planning, advanced surgical techniques, and vigilant postoperative care results in minimal morbidity and resolution of tumor symptomatology. A retrospective review of four consecutive pediatric patients with massive head and neck neurofibromas who underwent single-stage total or near-total removal of their tumors was performed. All four patients had obstructive airway symptoms. There were two minor complications. All patients had complete relief of their symptoms and return of function without any additional neurologic deficits. It is possible to safely achieve total or near-total removal of extensive plexiform neurofibromas with minimal morbidity while restoring lost function.     

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.