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PubMedDate not supplied

[Gastrointestinal neurofibromatosis. A rare cause of abdominal surgery].

OBJECTIVE: Report two cases of gastrointestinal neurofibromatosis that required surgical intervention for their resolution. BACKGROUND: Neurofibromatosis is a congenital disease which is classified in two types. In neurofibromatosis type 1 or Von Recklinghausen's disease the patients have some classical manifestations as cafe au lait pigmentation, bony abnormalities and neurofibromas of both peripheral and central nerves. In up to 25% of the patients with neurofibromatosis 1, the gastrointestinal tract is involved. The most affected organs are the stomach and the jejunum. The symptoms of the patients with gastrointestinal neurofibromatosis are related to gastrointestinal bleeding or obstruction. METHOD: Two patients with gastrointestinal neurofibromatosis that required surgical intervention for the resolution of their manifestations. RESULTS: Two cases of gastrointestinal neurofibromatosis, one of them had as her main clinical feature gastrointestinal bleeding, and the other patient intestinal obstruction. They were submitted to exploratory laparotomy finding gastrointestinal neurofibromatosis in both as the cause of their symptomatology. CONCLUSIONS: The management of gastrointestinal neurofibromatosis could need surgical intervention, and when this is done the postoperative evolution is satisfactory.

Adult↗
PubMed1999

The different forms of neurofibromatosis.

In the last two decades our knowledge of the natural history, genetics and management of the different forms of neurofibromatosis has changed. Of the numerical classifications of neurofibromatosis proposed in the past, only neurofibromatosis type 1 (Nf1) and neurofibromatosis type 2 (Nf2) have been shown to be distinct at clinical and molecular levels. Mosaicism has been demonstrated both in patients with Nf1 and in patients with Nf2, and features of segmental or mosaic Nf1 and Nf2 have been defined. The outlying phenotypes and the molecular genetics of other, rarer, types of neurofibromatosis have been delineated: these are hereditary spinal neurofibromatosis, Schwannomatosis, familial intestinal neurofibromatosis, autosomal dominant "cafe-au-lait spots alone", autosomal dominant "neurofibromas alone", Watson syndrome, Noonan/neurofibromatosis syndrome and the so-called syndrome of multiple naevi, multiple schwannomas and multiple vaginal leiomyomas. In this article I will review the different forms of neurofibromatosis, focusing on those aspects that most commonly challenge the neurosurgeon.

Genotype↗
PubMed2003

Neurofibromatosis--Noonan's syndrome with associated rhabdomyosarcoma of the urinary bladder in an infant: case report.

Neurofibromatosis 1 is an autosomal dominant disorder. Noonan's syndrome is known to be associated with neurofibromatoses. Patients with neurofibromatosis are predisposed to developing malignant tumors. The relationship between the genetic changes in the neurofibromin gene and mechanisms associated with tumor development in neurofibromatosis has been investigated. A non-sense mutation C2446T --> R816X of the neurofibromin gene has been detected in some patients with the neurofibromatosis 1-Noonan's syndrome phenotype. We describe a case of an infant with the overlapping features of neurofibromatosis 1 and Noonan's syndrome who presented with rhabdomyosarcoma of the urinary bladder. The genetic analysis of our patient revealed neither mutation in the neurofibromatosis 1-guanosine triphosphatase-activating protein-related domain nor the R816X nonsense mutation. The phenotypic and genotypic features of neurofibromatosis, Noonan's syndrome, and cases with the overlapping features of both syndromes have been reviewed. The presentation of our case underlines the importance of careful examination for the clinical features of neurofibromatosis and phenotypic traits of associated diseases, especially in patients with malignant tumors.

Biopsy↗
PubMed1987

Discounting an adverse maternal effect on severity of neurofibromatosis.

Neurofibromatosis, a common, progressive, autosomal dominant disorder, is markedly variable in its expressivity. Some authors have suggested that some contribution to neurofibromatosis's variability may be an adverse effect of a mother's neurofibromatosis on the overall severity seen in her offspring with neurofibromatosis. In the present study of 188 maternal affected, paternal affected, and sporadic von Recklinghausen neurofibromatosis cases, the maternal influence question was systematically examined. Overall severity, selected features most likely to reflect in utero maternal influence, and other common neurofibromatosis-I features were analyzed statistically. Age, racial composition, and gender of the three groups were similar. No significant differences were found (P less than or equal to .01) between maternal affected, paternal affected, and sporadic cases in terms of overall severity, probability of reaching advanced severity as a function of age, indications of possible prenatal influence (eg, congenital neurofibromas, tibial pseudarthrosis), or other neurofibromatosis features. These results demonstrate that the nature and severity of neurofibromatosis for maternal affected cases are essentially the same as for paternal affected and sporadic cases.

Adolescent↗
PubMed1994

Neuropsychological profile of children with neurofibromatosis, brain tumor, or both.

Neurofibromatosis type 1, a common autosomal dominant genetic disorder, is associated with numerous physical and medical anomalies as well as an increased incidence of learning disability. Tumors of the central nervous system have been estimated to occur in 15%, but their contribution to neuropsychological status is unknown. This study examines the relative contribution of neurofibromatosis and brain tumor to the cognitive profile of children with neurofibromatosis. A comprehensive battery of neuropsychological and behavioral tests was administered to a group of 65 children with neurofibromatosis type 1. Fourteen were then matched on demographic variables with two other groups of children who had either a brain tumor in addition to neurofibromatosis or a brain tumor alone. The two brain tumor groups were also matched on tumor type, location, and therapy. Mean scores of the neurofibromatosis-brain tumor group were generally the lowest of the three groups; those of the brain tumor group were highest, and performance of the neurofibromatosis group was generally between the other two groups. These results suggest that neurofibromatosis is, by itself, associated with significant cognitive morbidity, but that the severity of the problems is increased somewhat if a brain tumor is also present.

Adolescent↗
PubMed1993

Neurofibromatosis and pregnancy. An update.

Neurofibromatosis is one of the most frequent genetic diseases in humans. Pregnancy in neurofibromatosis patients is, however, less common. Most current information on pregnancy and neurofibromatosis is derived from case reports, which may not reflect the true situation. In the past 15 years only two series of pregnant neurofibromatosis patients were reported in the English-language literature. We present our experience with 34 pregnancies in nine neurofibromatosis patients who delivered at our medical center. While fertility does not seem to be impaired in neurofibromatosis, these patients experience a higher-than-expected rate of first-trimester spontaneous abortions (20.7%), stillbirths (8.7%) and intrauterine growth retardation (13.0%). A high rate of cesarean section (26%) was also observed in our series. We conclude that pregnant neurofibromatosis patients constitute a high-risk group, in danger of developing life-threatening complications. However, with proper antenatal care, most pregnant neurofibromatosis patients can deliver safety if the pregnancy continues beyond the first trimester.

Adult↗
PubMed2000

Mutations and allelic loss of the NF2 gene in neurofibromatosis 2-associated skin tumors.

Schwannomas in the skin are frequently observed in neurofibromatosis 2 patients. In about one-quarter of the cases, skin tumors are the first clinical symptoms of this disease. Recognizing neurofibromatosis-2-related skin tumors is therefore important for early diagnosis of neurofibromatosis 2, especially in pediatric patients. In this study, we examined 40 skin tumors (36 schwannomas and four neurofibromas) from 20 neurofibromatosis 2 patients for NF2 mutations and allelic loss. NF2 mutations have been identified in blood from 15 (75%) of the 20 patients. We found NF2 mutations in five (13%) and NF2 allelic loss in 18 (45%) of the 40 analyzed tumors. Genetic alterations (allelic loss or mutation) were thus found in 50 (63%) out of the total of 80 examined alleles. In 17 (43%) tumors, alterations were found on both NF2 alleles. These results suggest that, as in the case of vestibular schwannomas and meningiomas, loss of functional NF2 gene product is also the critical event in the development of skin schwannomas. Identification of genetic alterations of the NF2 gene in skin tumors may help to identify neurofibromatosis-2-associated skin tumors, thus assisting in the diagnosis of neurofibromatosis 2 in ambiguous cases, and excluding neurofibromatosis 1 in unclear cases. We also report that the detection rate of constitutional mutations was higher in patients with skin tumors (65%) than in patients without skin tumors (40%).

Genes, Neurofibromatosis 2↗
PubMed2005

Neurofibromatosis 1: from lab bench to clinic.

Neurofibromatosis type 1 is a common autosomal dominant disorder in which affected children and adults develop both benign and malignant tumors. In addition to tumor formation, children with neurofibromatosis type 1 may exhibit specific learning disabilities, distinctive bony abnormalities, and hyperpigmented lesions (cafe-au-lait macules, skinfold freckling, and Lisch nodules). With the identification of the neurofibromatosis 1 gene in 1990, significant strides have been made towards elucidating the pathogenesis of specific clinical problems in neurofibromatosis type 1 and developing first-generation, biologically based targeted therapies. Recent advances in mouse modeling have likewise yielded important insights into the genetic and cellular mechanisms underlying neurofibromatosis 1-associated tumor formation and learning disabilities. This review will focus on the clinical features of neurofibromatosis type 1, the molecular biology of the neurofibromatosis 1 gene, and the use of mouse modeling to recapitulate the human condition.

Animals↗
PubMed1995

Ocular abnormalities in neurofibromatosis 2.

PURPOSE: To evaluate the ocular abnormalities in patients with clinically diagnosed neurofibromatosis 2 and asymptomatic gene carriers. METHODS: Probands were ascertained through a surgical otolaryngology practice. In a cross-sectional study, we examined 49 patients with neurofibromatosis 2, 30 offspring of patients, and, as a comparison group, 18 parents and siblings of patients with sporadic neurofibromatosis 2. The examination included a complete neuro-ophthalmic assessment, physical examination, and, for patients and first-degree relatives at risk, cranial and spinal magnetic resonance imaging with gadolinium enhancement, if not previously performed. RESULTS: The most common ocular abnormalities were posterior subcapsular or capsular, cortical, or mixed lens opacities in 33 (67%) of 49 patients with neurofibromatosis 2 and retinal hamartomas in 11 (22%). We used segregation analysis to determine the mutation carrier status of six at-risk offspring who were 30 years old or younger in two multigeneration families. Three asymptomatic mutation carriers had cataracts, whereas those who were predicted not to carry the mutation did not have cataracts. Asymptomatic mutation carriers may have developmental abnormalities of the eye that are detectable in childhood or adolescence, a finding that may assist in early diagnosis of the disease. CONCLUSIONS: A variety of ocular abnormalities are present in neurofibromatosis 2, including cataracts, retinal hamartomas, and ocular motor deficits. Many of these are developmental or acquired early in life and may assist in presymptomatic diagnosis. For screening at-risk relatives of patients with neurofibromatosis 2, the types of cataract that are most suggestive of neurofibromatosis 2 are plaque-like posterior subcapsular or capsular cataract and cortical cataract with onset under the age of 30 years.

Adolescent↗
PubMed1987

Non-von Recklinghausen's neurofibromatosis presenting as hemifacial neurofibromas and contralateral café au lait spots.

The term neurofibromatosis designates a spectrum of disorders, the most common of which is von Recklinghausen's disease. We describe two patients with forms of neurofibromatosis other than von Recklinghausen's neurofibromatosis, characterized by involvement of half of the face and the contralateral lower extremity. Neither patient had a family history of neurofibromatosis, and a thorough evaluation of both patients failed to reveal evidence of von Recklinghausen's disease. The classification of neurofibromatosis is briefly summarized, with special emphasis placed on the need for a specific diagnosis regarding the type of neurofibromatosis for purposes of estimating prognosis and providing genetic counseling. The relationship between pregnancy and neurofibromatosis is also discussed.

Adult↗
PubMed2002

Unidentified bright objects associated with features of neurofibromatosis 1.

Unidentified bright objects are commonly observed on magnetic resonance imaging in young neurofibromatosis 1 patients, but their clinical and pathologic significance is largely unknown. Diagnostic features of neurofibromatosis 1 include café-au-lait spots, intertriginous freckling, Lisch nodules, neurofibromas, bony lesions, and optic glioma. We investigated the relationship between unidentified bright objects and other features of neurofibromatosis 1. Data from the National Neurofibromatosis Foundation International Database included 523 neurofibromatosis 1 patients between 2 and 20 years of age who had cranial magnetic resonance imaging examinations. The presence or absence of unidentified bright objects, diagnostic features of neurofibromatosis 1, and central nervous system neoplasms was known in these patients. Logistic regressive models were used to measure associations between unidentified bright objects and the other features while controlling for age. The occurrence of unidentified bright objects was associated with the number of diagnostic features, but most significantly with central nervous system neoplasms other than optic gliomas [odds ratio (OR) = 9.0, 95% confidence interval (CI) = 1.2-70], optic gliomas (OR = 2.1, 95% CI = 1.2-3.6), subcutaneous neurofibromas (OR = 2.0, 95% CI = 1.3-3.1), and Lisch nodules (OR = 1.6, 95% CI = 1.1-2.3). These findings suggest a common causal mechanism between unidentified bright objects and these cardinal clinical features in children with neurofibromatosis 1.

Adolescent↗
PubMed1997

Homozygous inactivation of the NF1 gene in bone marrow cells from children with neurofibromatosis type 1 and malignant myeloid disorders.

BACKGROUND: The risk of malignant myeloid disorders in young children with neurofibromatosis type 1 is 200 to 500 times the normal risk. The gene for neurofibromatosis type 1 (NF1) encodes neurofibromin, a protein that negatively regulates signals transduced by Ras proteins. Genetic and biochemical data support the hypothesis that NF1 functions as a tumor-suppressor gene in immature myeloid cells, but inactivation of both NF1 alleles has not been demonstrated in leukemic cells from patients with neurofibromatosis type 1. METHODS: Using an in vitro transcription and translation system, we screened bone marrow samples from 18 children with neurofibromatosis type 1 and myeloid disorders for NF1 mutations that cause a truncated protein. Mutations were confirmed by direct sequencing of genomic DNA from the patients, and from their affected parents, in cases of familial neurofibromatosis type 1. RESULTS: Specimens from 9 of the 18 children contained abnormal peptide fragments, and truncating mutations of the NF1 gene were found in specimens from 8 of these children. The normal NF1 allele was absent in bone marrow samples from five of the eight children. We detected the same mutation in DNA from the affected parent of each child with familial neurofibromatosis type 1. CONCLUSIONS: Both alleles of the NF1 gene are inactivated in leukemic cells in some patients with neurofibromatosis type 1. NF1 appears to function as a tumor-suppressor gene in immature myeloid cells.

Bone Marrow↗
PubMed1996

Prognostic significance of type 1 neurofibromatosis (von Recklinghausen Disease) in childhood optic glioma.

Although the association between optic glioma and neurofibromatosis is well recognized, few studies have systematically compared the outcomes of patients with optic gliomas and neurofibromatosis and patients with optic gliomas without neurofibromatosis. In the present study, patients with optic gliomas and Type 1 neurofibromatosis (NF-1) were compared with patients with optic gliomas without NF-1, with respect to survival, time to tumor progression, and tumor location. Forty-four patients with optic gliomas who were evaluated between 1949 and 1991 were studied retrospectively. Sixteen of 44 patients (36%) met the National Institutes of Health criteria for NF-1. The medical records of all patients were examined, and letters of inquiry were sent to every living patient to ascertain current health statuses. Death certificates were obtained to determine causes of death. Follow-up averaged 7.2 years (10.2 yr for patients with NF-1, 5.4 yr for patients without NF-1). The 5- and 10-year survival rates for patients with optic gliomas and NF-1 were 93 and 81%, respectively. For those patients with optic gliomas who did not have NF-1, 5- and 10-year survival rates were 83 and 76%, respectively. Seventeen patients experienced tumor progression (5 with NF-1, 12 without NF-1). A difference was observed in the mean time to tumor progression (first relapse) between the two groups (mean time with NF-1, 8.37 yr; without NF-1, 2.39 yr [P < 0.01]). However, no significant difference in overall survival, as evaluated by a log-rank test of the respective Kaplan-Meier survival curves, was observed between the two groups. A significant difference in distribution of tumor location between the group with NF-1 and the group without NF-1 was also noted (Fisher's exact test, P = 0.0338), although the number of patients evaluated in this series was too small to determine whether this difference in tumor location influenced relapse rate. We conclude that optic gliomas in patients with neurofibromatosis have a different distribution of location as opposed to those in patients without neurofibromatosis, and, for first relapse, the presence of neurofibromatosis is a significant favorable factor.

Adolescent↗
PubMed1985

Melanin macroglobules as a cellular marker of neurofibromatosis: a quantitative study.

To investigate the usefulness of melanin macroglobules (MMG) as a cellular marker for neurofibromatosis, their density was quantified in biopsies of café-au-lait spots (macules) (CALM) from 22 patients with von Recklinghausen's neurofibromatosis, 6 patients with bilateral acoustic neurofibromatosis, and 19 controls. The density of MMG was significantly higher in biopsies of the CALM of patients with von Recklinghausen's neurofibromatosis than in patients with bilateral acoustic neurofibromatosis (p less than .01) or controls (p less than .0008). The mode of acquisition of von Recklinghausen's neurofibromatosis (inherited vs new mutation) was not related to the density of MMG. On light microscopy, 14/22 (64%) patients with von Recklinghausen's neurofibromatosis had 11 or more MMG per 5 high-power fields. In contrast, none of the other two groups had more than 10 MMG per 5 high-power fields.

Adolescent↗
PubMed2002

Intracranial neoplasms in children with neurofibromatosis 1.

Neurofibromatosis 1 is associated with an increased risk for the development of benign and malignant tumors involving neural and non-neural tissues. Children as well as adults with neurofibromatosis 1 are affected. Central nervous system neoplasms represent a significant portion of these malignancies and appear primarily in children less than 10 years of age. Optic pathway gliomas and brainstem gliomas are the most common intracranial neoplasms found in neurofibromatosis 1, although there also is an increased incidence of other brain tumors in this population. The majority of these intracranial neoplasms are benign pilocytic astrocytomas, which may behave in a less aggressive manner than histologically identical tumors in non-neurofibromatosis 1 patients. Owing to the indolent nature of these tumors, conservative management with close follow-up is recommended. When intervention is required, conventional treatment with surgery, radiation, or chemotherapy has been used with variable results. The current challenge lies in understanding the pathogenesis of gliomas in neurofibromatosis 1, which may lead to the development of biologically directed therapies with less associated morbidity and mortality for neurofibromatosis 1 as well as non-neurofibromatosis 1 children.

Brain↗
PubMed1989

Neurofibromatosis and other disorders among children with CNS tumors and their families.

We conducted a population-based case-control study with 338 patients, less than 15 years of age, diagnosed with a primary tumor of the central nervous system from January 1968 through December 1977 in 53 New York State counties. The study also included 676 controls selected from the birth certificate files of the New York State Department of Health. We collected information on neurofibromatosis and congenital anomalies in study subjects, their siblings and parents by telephone interview with the mother of each case and control. We obtained supplemental information on neurofibromatosis in the patients and their families from hospital medical records. This study confirmed the strong association of neurofibromatosis with risk of CNS tumors. Thirteen cases and no controls had neurofibromatosis. Two fathers and 3 mothers of cases had neurofibromatosis. Five cases had siblings with neurofibromatosis. None of the first-degree relatives of controls had neurofibromatosis. We observed a relative risk of 4.49 for history of seizures. Seizures are often among the presenting symptoms for CNS tumors. We observed no difference between cases and controls in the occurrence of congenital anomalies. There was a nonsignificant excess of congenital anomalies among siblings of cases compared with controls. This decreased to 1.13 when adjusted for number of siblings.

Brain Neoplasms↗
PubMed1987

Duodenal carcinoid tumours, phaeochromocytoma and neurofibromatosis: islet cell tumour, phaeochromocytoma and the von Hippel-Lindau complex: two distinctive neuroendocrine syndromes.

To clarify neuroendocrine syndromes we have reviewed the association of neurofibromatosis with carcinoid tumours and of neurofibromatosis, phaeochromocytoma or von Hippel-Lindau complex with either carcinoid or islet cell tumours. In nine cases of neurofibromatosis with a carcinoid tumour studied all carcinoid tumours were in the duodenum, were distinctive histologically and had widespread somatostatin immunoreactivity. The duodenum was the primary site in 18 of 20 further published cases of carcinoid tumour and neurofibromatosis. Phaeochromocytoma was also present in six of these 27 cases with neurofibromatosis and duodenal carcinoid tumour. Six patients have been reported with Von Hippel-Lindau complex, phaeochromocytoma and islet cell tumour. A further 11 patients showed phaeochromocytoma and islet cell tumour. No cases of Von Hippel-Lindau complex had a carcinoid tumour, and no cases of neurofibromatosis had an islet cell tumour. We conclude that the association of neurofibromatosis, duodenal carcinoid tumour and phaeochromocytoma forms a distinctive neuroendocrine syndrome, sharply separated from the association of Von Hippel-Lindau complex with islet cell tumour and phaeochromocytoma. This separation is important in pathogenesis, diagnosis and clinical management.

Adenoma, Islet Cell↗
PubMed1994

Otologic manifestations of neurofibromatosis.

A chart review of 440 patients with neurofibromatosis seen at the Children's Hospital of Philadelphia Neurofibromatosis Clinic between 1980 and 1991 was performed to look for otologic manifestations. Neurofibromatosis 1 was present in 434 patients, and neurofibromatosis 2 was present in 6. A total of 31 otologic abnormalities related to neurofibromatosis were found in 28 patients. Neurofibromas of the external ear, including the pinna and the external auditory canal, were the most common finding. Middle ear neurofibromas were found in two patients. Acoustic neuromas were seen exclusively in patients believed to have neurofibromatosis 2. One cerebellopontine angle neurofibrosarcoma was found in a patient with neurofibromatosis 1.

Adolescent↗