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PubMed1996

Functional nerve growth factor receptor in von Recklinghausen neurofibromatosis: an immunocytochemical and short-term culture study.

Immunocytochemistry reveals 75 kDa low affinity type nerve growth factor receptor (NGFR) on the cell membrane of human neurofibroma cells of von Recklinghausen disease in vivo and in vitro. NGF-immunoreactivity is detected in the primary and cultured tumor cells. Growth augmentation of cultured neurofibroma cells by exogenous NGF is also confirmed. Phosphotyrosine-immunoreactivity is demonstrated by immunocytochemistry in the in vivo and in vitro neurofibroma cells suggesting possible phosphorylation of tyrosine residue in the NGFR or a cellular protein downstream of signal transduction through the ligand receptor system. These results indicate human neurofibroma cells possess functional NGFR and the growth is potentiated through the NGF-NGFR system in the paracrine and/or autocrine fashion.

Adult↗
PubMed2006

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.

Adult↗
PubMed2002

April 2002: 35-year-old healthy man with enlarging right parotid mass.

The April 2002 Case of the Month (COM). 35-year-old healthy man developed a mass in the right parotid gland. A superifical parotidectomy was performed for a 4.5 x 1.5 x 1.5 cm mass involving the intraparotid facial nerve. Grossly the tumor was multinodular, smooth and yellow with normal surrounding salivary gland. Microscopically, the tumor showed expanding nodules composed of proliferating fibroblasts, Schwann cells, and perineural-like cells in a myxoid stroma. Normal peripheral nerve twigs were identified in the periphery of the tumor. There was no increased mitotic activity, cellularity or nuclear pleomorphism. S-100 immunohistochemical stain was positive. The tumor was diagnosed as a solitary plexiform neurofibroma. Plexiform neurofibromas in this area have been described in children with von Recklinghausen's disease or neurofibromatosis 1 (NF 1). Plexiform neurofibromas typically involve deep seated nerve trunks and is considered pathognomonic for NF 1. This unusual case represents a solitary variant of plexiform neurofibroma presenting as a parotid mass in an adult patient without a personal stigmata or family history of NF 1.

Adult↗
PubMed1991

Benign spinal nerve sheath tumors: their occurrence sporadically and in neurofibromatosis types 1 and 2.

Benign spinal nerve sheath tumors (neurofibromas and schwannomas) often occur on dorsal nerve roots sporadically or in neurofibromatosis types 1 and 2. These are histologically benign tumors, and distinction between them is frequently not made by clinicians. To determine if there is a correlation between the histological pattern of benign spinal nerve sheath tumors and the type of neurofibromatosis, the clinical and pathological features of these tumors (86 surgical specimens and five autopsies) in 68 patients were reviewed. The patients were classified into one of four categories: neurofibromatosis type 1, neurofibromatosis type 2, uncertain, or sporadic. The diagnostic criteria used for neurofibromatosis types 1 and 2 were established by the National Institutes of Health. Patients who did not fulfill criteria for either neurofibromatosis type 1 or 2 but who had multiple nervous system tumors or other stigmata of neurofibromatosis were designated "uncertain." Spinal nerve sheath tumors were considered sporadic in 42 cases (40 schwannomas and two neurofibromas). In the 14 patients with neurofibromatosis type 1, all spinal nerve sheath tumors were neurofibromas. In six of the seven patients with neurofibromatosis type 2, all spinal nerve sheath tumors were schwannomas. One patient with neurofibromatosis type 2 had a spinal nerve sheath schwannoma and a tumor with features of both tumor types. The authors conclude that spinal nerve sheath tumors in patients with neurofibromatosis type 1 are neurofibromas. In contrast, spinal nerve sheath tumors occurring in neurofibromatosis type 2 or sporadically are most frequently schwannomas. The distinct histological features of these tumors may reflect different pathogenetic mechanisms even though they arise at identical sites in neurofibromatosis types 1 and 2.

Humans↗
PubMed1999

[Association of spheno-orbital dysplasia with plexiform neuroma in von Recklinghausen's neurofibromatosis].

We report a case of plexiform neurofibroma of the upper eyelid associated with spheno-orbital dysplasia in a 18-year-old woman with von Recklinghausen neurofibromatosis. Visual acuity was 20/40 in the right eye and 20/20 in the left. Plexiform neurofibroma involving the right upper eyelid was associated with mild ptosis and ipsilateral facial hypertrophy. Biomicroscopic examination showed lisch nodules. Funduscopic examination, visual field and neurologic examinations were normal. Café au lait spots involved the trunk with neck plexiform neurofibroma. Computed tomography disclosed spheno-orbital dysplasia. The patient's status remained unchanged at 6 months follow-up. Cranial features of von Recklinghausen neurofibromatosis are found in 3 to 7% of patients. In patients with plexiform neurofibroma of the eyelid the ophthalmologist should look for associated spheno-orbital dysplasia.

Adolescent↗
PubMed1991

Peripheral nerve sheath tumours: an ultrastructural study of 30 cases.

This report deals with the ultrastructural observations of 30 peripheral nerve sheath tumours [PNST], which include 25 schwannomas of acoustic nerve, one schwannoma of cauda equina, one neurofibroma from a case of Von Recklinghausen's disease, one pigmented neurofibroma of spinal nerve root and a malignant schwannoma of frontal region. Interdigitating slender cytoplasmic processes covered with a continuous layer of basal lamina constitute the single most important ultrastructural attribute of Schwann cells. Myelin formation was encountered in the cell processes of four out of 25 acoustic schwannomas. In four cases Microtubular arrays identical to that in an axon were seen in Schwann cells. These two observations require further support by additional cases of PNST studies by electron microscopy. The neurofibroma consisted only of Schwann cells and no ultrastructurally identifiable perineurial cells or fibroblasts were detected. The cells in the pigmented neurofibroma revealed submicroscopic features of both Schwann cell and melanocyte, indicating their common ancestry. A unique case of malignant schwannoma arising from frontal meninges is illustrated and it is emphasized that electron microscopy is mandatory for a correct histogenetic diagnosis of malignant tumours which occur at unexpected anatomical sites.

Adult↗
PubMed1988

Expression of selected growth factors and oncogenes in neurofibrosarcomas complicating von Recklinghausen disease.

One neurofibrosarcoma from each of three patients with von Recklinghausen neurofibromatosis (VRNF) was studied for the expression of selected growth factor genes and oncogenes. Comparative analyses were also performed on four neurofibromas and skin, nerve and muscle specimens from one of the patients with neurofibrosarcoma, an autopsy kidney specimen from a fifth VRNF patient, and normal liver and term placenta specimens from healthy control subjects. Northern blot hybridization techniques were used to analyze the amounts and sizes of mRNA resulting from the expression of eight genes. Insulin-like growth factor I showed a moderate level of expression in normal nerve and lower expression in two neurofibrosarcomas. Insulin-like growth factor II was moderately to heavily expressed in all specimens, and differential splicing patterns were seen. Platelet-derived growth factor showed low levels of expression in all three neurofibrosarcomas, skin, nerve, muscle and normal liver, low to moderate levels of expression in the neurofibromas, and high expression in normal control placenta. Beta-nerve growth factor was expressed at low levels in two neurofibrosarcomas and skin, but was not seen in other specimens. N-myc showed a low level of expression in one neurofibrosarcoma and a neurofibroma, and a higher level of expression in a second neurofibrosarcoma (and in this same subject's skin and nerve). Tissue-type plasminogen activator showed moderate levels of expression in two neurofibrosarcomas and one neurofibroma, but it was not seen in skin, nerve, kidney and normal term placenta specimens.

Blotting, Northern↗
PubMed2003

Clinical risk factors for mortality in patients with neurofibromatosis 1: a cohort study of 378 patients.

OBJECTIVE: To identify the main clinical features associated with mortality in patients with neurofibromatosis 1. DESIGN: Cohort study. SETTING: Referral center for neurofibromatosis. PATIENTS: Three hundred seventy-eight patients with neurofibromatosis 1 who had more than 1 year of follow-up in the center. MAIN OUTCOME MEASURES: Mortality. Clinical features, especially dermatological, were evaluated as potential factors associated with mortality. RESULTS: Factors associated independently with mortality were the presence of subcutaneous neurofibromas (odds ratio, 10.8; 95% confidence interval, 2.1-56.7; P<.001), the absence of cutaneous neurofibromas (odds ratio, 5.3; 95% confidence interval, 1.2-25.0; P =.03), and facial asymmetry (odds ratio, 11.4; 95% confidence interval, 2.6-50.2; P<.01). CONCLUSIONS: Some features that can be found by a routine clinical examination are associated with mortality in patients with neurofibromatosis 1. Clinical follow-up should be focused on patients with subcutaneous neurofibromas and/or the absence of cutaneous neurofibromas and/or facial asymmetry.

Adolescent↗
PubMed1996

Neurofibromatosis type 1 and pregnancy.

Neurofibromatosis Type 1 (NF-1) is an autosomal dominant condition which has markedly variable clinical expression, with manifestations ranging from mild cutaneous lesions to severe orthopedic complications and functional impairment. The current obstetrical literature indicates that women with NF-1 have increased complications associated with pregnancy. However, the majority of publications are case reports involving no more than 11 patients each, and are likely biased toward reporting on cases in which complications occurred. This study presents data on pregnancy outcome in 105 women with NF-1. The data were obtained from questionnaires completed by the study participants, and by review of their pregnancy and peripartum medical records. The 105 women had a total of 247 pregnancies, resulting in 182 live births, 44 first trimester spontaneous abortions, 21 elective terminations, and 2 ectopic pregnancies. There were two sets of twins. The cesarean section rate in our series (36%) was greater than the general population rate (9.1-23.5%). In 7 of these patients, the cesarean section was required because of maternal NF-1 complications. The study did not show the previously reported increased incidence of preeclampsia, preterm delivery, intrauterine growth restriction, pregnancy-induced hypertension, stillbirth, spontaneous abortion, or perinatal mortality. Sixty-four (60%) of the one hundred five women reported growth of new neurofibromas during pregnancy and fifty-five (52%) noted enlargement of existing neurofibromas. Nineteen women observed no changes in the size of their neurofibromas and no growth of new neurofibromas during pregnancy.

Cesarean Section↗
PubMed2000

Associations of clinical features in neurofibromatosis 1 (NF1).

Neurofibromatosis 1 (NF1), an autosomal dominant disease, exhibits extreme clinical variability. This variability greatly increases the burden for affected families and impairs our ability to understand the pathogenesis of NF1. Recognition of heterogeneity within a disease may provide important pathogenic insights, therefore we tested clinical data from three large sets of NF1 patients for evidence that certain common features are more likely to occur in some NF1 patients than in others. Clinical information on 4,402 patients with NF1 was obtained from three independent databases. We examined associations between pairs of clinical features in individual affected probands. We also examined associations between the occurrence of individual features in affected relatives. Associations were summarized as odds ratios with 95% confidence intervals. We found associations between several pairs of features in affected probands: intertriginous freckling and Lisch nodules, discrete neurofibromas and plexiform neurofibromas, discrete neurofibromas and Lisch nodules, plexiform neurofibromas and scoliosis, learning disability or mental retardation and seizures. We also found associations between the occurrence of Lisch nodules, macrocephaly, short stature, and learning disability or mental retardation as individual features in parents and children with NF1. Our observations suggest that, contrary to established belief, some NF1 patients are more likely than others to develop particular manifestations of the disease. Genetic factors appear to determine the development of particular phenotypic features.

Adult↗
PubMed2002

Analysis of intrafamilial phenotypic variation in neurofibromatosis 1 (NF1).

The relationship of genetic factors to variable expressivity in neurofibromatosis 1 (NF1) is poorly understood. We examined familial aggregation of NF1 features among different classes of affected relatives. Clinical information was obtained from the National NF Foundation International Database on 904 affected individuals in 373 families with 2 or more members with NF1. We used multivariate probit regression to measure the associations between various classes of relatives for each of 10 clinical features of NF1, while simultaneously adjusting for covariates including related features, age, and gender. Two distinct patterns were observed when we compared associations between first- and second-degree relatives, sibs, and parent-child pairs: Lisch nodules and café-au-lait spots had greater associations between first-degree relatives than between second-degree relatives, while subcutaneous neurofibromas, plexiform neurofibromas, café-au-lait spots, and intertriginous freckling had greater associations between sibs than between parents and children. In addition, Lisch nodules, subcutaneous neurofibromas, and cutaneous neurofibromas had greater associations between affected fathers and children than between affected mothers and children. These familial patterns suggest that unlinked modifying genes and the normal NF1 allele may both be involved in the development of particular clinical features of NF1, but that the relative contributions vary for different features.

Female↗
PubMed2006

Brachial plexopathy due to malignant peripheral nerve sheath tumor in neurofibromatosis type 1: case report and subject review.

Neurofibromatosis type 1 (NF1) is a common tumor predisposition syndrome affecting approximately 1 in 4,000 persons. It is an autosomal-dominant disorder with half of the cases resulting from spontaneous mutations. This genetic defect leads to the formation of benign tumors or neurofibromas of the peripheral nervous system. Dermal neurofibromas may cause local discomfort and itching but are rarely associated with neurological deficit and do not undergo malignant change. The more extensive plexiform neurofibromas produce neurological complications in 27%-43% of patients with NF1 and may undergo malignant degeneration in 5% of cases. Patients with NF1 who develop pain or new neurological symptoms should have a rapid and thorough assessment for malignancy. In this report, we illustrate this point by presenting a patient who developed acute shoulder pain and weakness due to malignant degeneration of a plexiform neurofibroma involving the left brachial plexus, and review the literature on this subject.

Brachial Plexus Neuropathies↗
PubMed2006

Persistent respiratory symptom can be a manifestation of neurofibromatosis-1.

A 3-year old boy with neurofibromatosis-1 presented with persistent respiratory symptoms and X-ray changes. High resolution computerised tomography (CT), bronchoscopy and spiral CT showed a mediastinal mass encasing and compressing the left main stem bronchus. Surgical removal and histology of the mass revealed a neurofibroma. Repeat scan six months post-surgery showed some persistence of the mass. Symptomatic, mediastinal neurofibroma in the paediatric age group is very rare. We could not find any previous report of a neurofibroma encasing the mediastinal structures. This case also demonstrates that persistent respiratory symptom in a patient with neurofibromatosis-1 warrants a search for intra-thoracic neurofibroma.

Humans↗
PubMed1998

Neurofibromatosis of the colon and rectum combined with other manifestations of von Recklinghausen's disease: report of a case.

Gastrointestinal involvement of neurofibromatosis occurs in as many as 25 percent of cases. Neurofibroma occurs most frequently in the stomach and jejunum, but the colon may also be involved. This condition is characterized by multiple submucosal neurofibromas of the gastrointestinal tract and café au lait pigmentation, bony abnormalities, and neurofibromas of both central and peripheral nerves. The lesions consist of an overgrowth of neural tissue along with other mesenchymal elements. Gastrointestinal neurofibromas may cause occult bleeding, luminal obstruction, or intussusception. Malignant transformation into neurofibrosarcoma is rare. We encountered a case of neurofibromatosis diffusely involving the left colon, the sigmoid colon, and the rectum, which resulted in herniation of the mass through the anus, with intestinal obstruction. The patient also showed skin lesions of the neurofibromatosis. We report this case with a review of the literature.

Colectomy↗
PubMed1996

[Involvement of the large intestine in neurofibromatosis type 1].

This report presents the cases of two female patients aged 54 and 57 years, both with colon involvement of type 1 neurofibromatosis. The first woman had a polypoid neuronal hyperplasia containing small Wagner-Meissner corpuscles, which had allowed identification of the neuronal nature of the lesion in a small mucosal biopsy specimen taken previously. The second patient had an idiopathic megacolon of the sigmoid, which had to be extirpated because of acute obstruction and ileus. Morphological examination revealed a typical plexiform neurofibroma of the bowel wall and neuronal hyperplasia of the colonic mucosa and submucosa, which had obviously caused disordered gut mobility leading to functional stenosis and extreme dilatation of prestenotic bowel parts. Gastrointestinal neurofibromatosis is rare and is characterized morphologically by neuronal hyperplasia of the mucosa and submucosa, sometimes containing small aggregates of ganglion cells by which it can easily be identified. However, in the majority of cases the increase of proliferating mucosal nerve fibres can only be confirmed by S-100 protein immunostaining. Furthermore, solitary, multiple and plexiform neurofibromas are found, but only the last, which arises from mesenteric or subserosal nerves, is virtually pathognomonic for neurofibromatosis. Gastrointestinal neurofibromas are usually late manifestations of the disease, but in exceptional cases they can be the initial sign of neurofibromatosis in patients who have no external stigmata that arouse suspicion. The occurrence of gastrointestinal neurofibromas should therefore lead to a careful search for other features of NF-1 in the affected patients and in their families.

Adenomatous Polyposis Coli↗
PubMed1999

[Cutaneous neural neoplasms--an update].

Until recently, benign cutaneous neural tumours which do not fulfil criteria for either neurofibrom or schwannoma often were lumped into the broad category of benign peripheral nerve sheath tumours (PNST). However, during the last years a number of new entities of neural tumours have been described, and advances in immunohistochemistry and electronmicroscopy have helped us to better understand the cytological differentiation in these neoplasms. The knowledge of these distinctive neoplasms is necessary in order to avoid diagnostic pitfalls and misdiagnosis of more aggressive neoplasms. These distinctive lesions include: neurothekeoma, which can divided into classical myxoid and cellular types showing characteristic histological and immunohistochemical features. Typical neurothekeoma (nerve sheath myxoma) is a lobular or nodular dermal neoplasm composed of plump spindled or stellated, S-100 positive tumour cells set in a maxoid stroma. In contrast, cellular neurothekeoma is characterized as an ill-defined dermal neoplasm composed of concentric nests and fascicles of spindle-shaped and epithelioid tumour cells, which are S-100 negative but stain positively for NKIC3. The evidence of intermediate forms of neurothekeoma showing features of ordinary hypocellular neurothekeoma and cellular neurothekeoma, as well as ultrastructural studies, emphasize that both variants represent a spectrum of neurothekeoma; solitary circumscribed neuroma ("palisaded encapsulated neuroma") manifests mainly as a skin-colored or pink papule or nodule, and is most often located on the face. Histologically, solitary circumscribed neuroma is a well-circumscribed round or ovoid dermal neoplasm composed of interwoven fascicles of schwann cells, which stain positively for S-100 protein and numerous neurofilament positive axons surrounded partly by fibroblasts and EMA-positive perineural cells; perineurioma is a rare well-circumscribed neoplasm which occurs mainly in subcutaneous tissue and only rarely in the dermis and in deep soft tissues. Perineurioma is composed of elongated bipolar spindle-shaped tumour cells which are arranged in storiform, whorled, linear or lamellated growth patterns, The tumour cells stain positively for vimentin and EMA, and for CD 34 in a number of cases, but lack positivity for S-100 protein, neurofilament and desmoplakin. In addition unusual forms of schwannoma (cellular schwannoma, solitary plexiform schwannoma, melanotic schwannoma) and neurofibroma ("atypical" (bizarre) neurofibroma, diffuse neurofibroma, epithelioid neurofibroma) are briefly discussed.

Humans↗
PubMed1994

31P NMR phospholipid characterization of intracranial tumors.

Phospholipid extracts from 48 intracranial tumors were analyzed using 31P NMR. Phospholipids commonly identified in the tumor spectra included phosphatidylglycerol (PG), phosphatidic acid (PA), diphosphatidylglycerol (DPG), uncharacterized phospholipid (U), ethanolamine plasmalogen (EPLAS), phosphatidylethanolamine (PE), phosphatidylserine (PS), sphingomyelin (SM), lysophosphatidylcholine (LPC), phosphatidylinositol (PI), a choline phospholipid (CPLIP), and phosphatidylcholine (PC). Differences in the mean relative mole-percentage of phosphorus concentrations of individual phospholipids were used to differentiate among tumors. Neural sheath tumors (neurilemmoma, neurofibroma and fibrosarcoma) were noted to contain significantly elevated levels of SM relative to tumors of neural glial origin and individually, glioblastoma multiforme was noted to contain depressed levels of SM relative to neurilemmoma, neurofibroma and meningioma. Significantly decreased levels of PA were noted for glioblastoma relative to neurilemmoma along with significantly decreased levels of PE relative to meningioma. Elevated levels of LPC and CPLIP were seen in glioblastoma multiforme relative to meningioma. Additional findings included elevated levels of PC for glioblastoma multiforme relative to neurofibroma, and neurilemmoma was differentiated from neurofibroma with elevated levels of PA and depressed levels of PI. 31P NMR phospholipid analysis provides supplemental biochemical information which may be used to improve the interpretation of spectra acquired in vivo, and reveals important tumor-specific biochemical information which may further improve the understanding of the biological behavior of intracranial tumors.

Brain Chemistry↗
PubMedDate not supplied

Enlarging tongue masses in neurofibromatosis type 1: MR findings of two cases.

Plexiform neurofibromas usually occur in the neck, pelvis, and extremities. Jaws and oral cavity plexiform neurofibromas have also been described. Magnetic resonance (MR) patterns for neurofibromas are typical. They include low-to-intermediate signal intensity on T1-weighted images, enhancement of the solid component of the tumor after contrast medium administration, heterogeneity on T2-weighted images, and in some cases, multiple target signs due to a collagen central area. We report MR findings of two neurofibromatosis type 1 (NF1) patients with enlarging tongue plexiform neurofibromas.

Adolescent↗