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At least 1,045 records · Page 58Linked to original sources
PubMed1995

[Neurofibromatosis (von Recklinghausen disease) and carcinoid tumor in Vater's ampulla].

The localization of the carcinoid tumors of the gastrointestinal tract--as a part of the APUD system--is extremely seldom at the region of ampulla of Vater. A case of congenital neurofibromatosis is reported in a 49-year-old male patient, with a carcinoid tumor of the ampulla of Vater in the background of long-standing, atypical biliary complaints. Periampullary neoplasm of neural-crest origin are very rare, up to this time 73 cases of Vater papilla carcinoid tumors were described. Regarding the development of VP carcinoid in neurofibromatosis, our patient is the 21st reported case in the world literature, and the first one in Hungary. The authors review the literature, giving special attention to the risk of periampullary neoplasms in von Recklinghausen's disease, the need of accurate diagnosis and the correctly selected operative intervention.

Ampulla of Vater↗
PubMed1995

Neurofibromatosis of the skull base.

Neurofibromatosis of the skull base is a syndrome that may occur in an isolated fashion or as a component of Von Recklinghausen disease. This article discusses the clinical features of neurofibromatosis, diagnostic methods, and surgical treatment.

Adult↗
PubMedDate not supplied

Orthopaedic complications of childhood neurofibromatosis.

Neurofibromatosis is a genetically transmitted, multisystemic disorder characterized by abnormalities of the skin, nervous tissue, and bone. Many of the serious problems associated with this disease are orthopaedic in nature. The treatment and plan of care for a child with neurofibromatosis must be comprehensive and consistent. Nursing care should address the developmental, physical, and emotional needs of the child, as well as the psychologic concerns and educational needs of the child and parents.

Bone Diseases↗
PubMedDate not supplied

Orthopaedic complications of childhood neurofibromatosis.

Neurofibromatosis is a genetically transmitted, multisystemic disorder characterized by abnormalities of the skin, nervous tissue, and bone. Many of the serious problems associated with this disease are orthopaedic in nature. The treatment and plan of care for a child with neurofibromatosis must be comprehensive and consistent. Nursing care should address the developmental, physical, and emotional needs of the child, as well as the psychologic concerns and educational needs of the child and parents.

Bone Diseases↗
PubMed1994

Gastrointestinal hemorrhage complicating systemic neurofibromatosis.

A case of gastrointestinal hemorrhage caused by small bowel neurofibromas in a gentleman with systemic neurofibromatosis is presented. The multiple presentations of gastrointestinal system involvement by neurofibromatosis are reviewed. Early diagnosis and localization of small bowel tumors remains a dilemma. Mesenteric angiography and early surgical intervention are recommended.

Gastrointestinal Hemorrhage↗
PubMed1994

Head and neck manifestations of neurofibromatosis.

The neurofibromatoses are one of four neurocutaneous syndromes inherited in an autosomal dominant pattern and characterized by generalized cutaneous neurofibromas. They are often associated with central and peripheral nervous system tumors, café-au-lait spots, skeletal abnormalities, and a myriad of associated abnormalities. Neurofibromatosis 1 (NF-1) and neurofibromatosis 2 (NF-2) are clinically and genetically distinct diseases. The diseased gene for NF-1 is the long arm of chromosome 17 and for NF-2 it is the long arm of chromosome 22. Universal signs for NF-1 include Lisch nodules (melanocytic iris hamartomas), optic nerve gliomas, and axillary freckling. The hallmark of NF-2 is bilateral acoustic neuromas. The incidence of head and neck lesions in NF-1 and NF-2 is approximately 37% with a 3.5% malignant transformation rate. A team approach is essential for management of both NF-1 and NF-2 due to multiple organ system involvement.

Head and Neck Neoplasms↗
PubMed1994

[Diffuse corneal pigmentation--a new sign in neurofibromatosis].

Neurofibromatosis is an autosomal dominant disease affecting many organs. It is known for the characteristic pigmented skin spots and various neurofibromas. We present a 79-year old man who underwent elective cataract extraction. The surgery was complicated by the presence of diffuse, deep, intracorneal pigmentation. To our knowledge, this sign has not as yet been described in neurofibromatosis.

Aged↗
PubMedDate not supplied

Immune dysfunction in experimental versus naturally occurring neurofibromatosis in damselfish.

Damselfish neurofibromatosis [DNF], a neoplastic disease characterized by multiple, neurofibromas and malignant schwannomas, is currently the only naturally occurring animal model of human neurofibromatosis type-1. Previous studies of immune function in DNF affected fish indicated the potential for significant immunosuppression in advanced stages of the disease. The current study compares healthy animals with fish captured in the wild bearing spontaneous tumors and with animals bearing experimental tumors transmitted in the laboratory. In order to determine the effects of tumor burden on the immune capabilities of these animals, proliferative responses to mitogens and toward allogeneic cells were tested. The data presented here indicate that animals bearing advanced tumors of experimental origin are profoundly immunocompromised. Similarly, some spontaneous tumor-bearing animals are deficient in proliferative immune responses, and splenocytes from most animals fail to respond to mitogens. However, a proportion of animals with stage 5 spontaneous tumors retain immune reactivity, and are capable of alloreactions comparable to those of normal individuals when stimulated with cells from healthy [4/10, 40%] or other tumor-bearing [4/8, 50%] animals. The contributions of tumor size, distribution and cytokine production to the differential immune impairment are discussed.

Animals↗
PubMed1993

[Cranio-encephalitic manifestations in neurofibromatosis. A study with magnetic resonance and computed tomography].

We present the cranioencephalitic alterations of twelve patients with neurofibromatosis (eleven type 1 and one type 2) we studied using both computed tomography (CT) and magnetic resonance (MR). In addition, we made a comparison of the two techniques. MR allows greater differentiation of gliomas, neurinomas, and neurofibromas and better characterizes tumoral vascularization. Lesions undetected by CT can be identified, and it is a non-invasive method. For these reasons, we consider MR the technique of choice in the study of neurofibromatosis, even though CT continues to be superior in examining osteal dysplasias and calcifications and should thus be used as a complementary technique for an exact assessment of the lesions.

Adolescent↗
PubMed1993

[Gastrointestinal manifestations in neurofibromatosis].

Gastrointestinal involvement in neurofibromatosis occurs in three major forms: solitary neurogenic tumours, diffuse ganglioneuromatosis and visceral vasculopathy. The entire gastrointestinal tract may be affected. According to the literature, 10-25% of the patients with neurofibromatosis develop intestinal manifestations. However, the recorded incidence is probably too low, since many cases are undiagnosed. Two cases of large plexiform neurofibromas and diffuse ganglioneuromatosis of appendix and intestine are reported.

Adolescent↗
PubMedDate not supplied

[Isolated and spontaneously regressive colonic neurofibromatosis].

This case report concerns a man presenting protein losing enteropathy. Multiple polypoid colonic lesions were discovered corresponding to intra and submucosal neurofibromas. No extradigestive sign was noticed, and the diagnosis of isolated colonic neurofibromatosis was upheld. Eight years later, it was observed that both protein losing enteropathy and the colonic neurofibromas had apparently spontaneously disappeared. Isolated digestive neurofibromatosis and spontaneous tumoural regressions are discussed.

Colonic Neoplasms↗
PubMedDate not supplied

[Digestive hemorrhage in a patient with multiple neurofibromatosis].

Neurofibromatosis is an autosomal dominant trait with variable expressivity clinically defined by the coexistence of multiple cafè au lait spots, subcutaneous neurofibromas and Lisch nodules. Hemorrhage from intestinal neurofibromas or related tumors may be life-threatening because often inaccessible and therefore difficult to locate. The Authors report a case of gastrointestinal hemorrhage in a 68 year old patient with neurofibromatosis who had an episode of melena from duodenal ulcer endoscopically detected 5 years earlier. Endoscopy failed to discover the site of bleeding; this was successfully demonstrated by angiography: superior mesenteric arteriography disclosed 32 hypervascular masses supplied by a digiunal branch and by the oleo-colic artery. Because of continuing hemorrhage the patient was submitted to surgery. The exploration demonstrated ulcerated neurofibromatous neoplasms at the level of the digiunum and terminal ileum, with a Meckel's diverticulum and gallbladder stones. Intestinal resection, right emicolectomy, Meckel's diverticulum resection and colecystectomy were performed. Review of the literature demonstrates angiography is the most reliable imaging modality for detecting such tumors.

Aged↗
PubMed1997

Single K channel currents in Schwann cells from normal and neurofibromatosis-affected damselfish.

Damselfish neurofibromatosis is a naturally occurring disease of a tropical marine fish species. Affected fish exhibit peripheral nerve sheath tumors which contain morphologically abnormal Schwann cells (SC), similar to tumors encountered in the human disease neurofibromatosis type 1. Unitary A-type K channels in cell-attached membrane patches of SC were studied. Three different K channel conductances of approximately 5, 10, and 15 pS were present in both normal SC (n = 10) and tumored SC (n = 9). The variability in K channel conductance coincided with a large range of both mean open time and open probability in patches from normal and tumored SC. Channel open time histograms were fit by a single exponential. The ranges of time constants for open times irrespective of conductance were 0.26-9.3 msec in patches from normal cells and 0.60-0.73 msec in patches from tumored cells. These ranges were not significantly different. Inactivation time constants from ensemble averages of single channel currents averaged 83 +/- 46 msec for normal SC and 44 +/- 26 msec for tumored SC, which were not significantly different. These results suggest that A-type K currents from fish SC are composed of channels exhibiting multiple conductances and a variety of inactivation rates, which may account for the range of inactivation observed in whole cell currents but whose activity in membrane patches may not be wholly applicable to the whole cell currents.

Animals↗
PubMed1997

[NF1 (neurofibromatosis type 1)].

Several distinct Ras GTPase activating proteins (GAPs) from mammals, including Ras GAP of 120 kDa (GAP1) and NF1, stimulate the intrinsic GTPase activity of normal Ras, but not oncogenic Ras mutants (Trahey and McCormick, 1987). That is the reason why normal Ras remains predominantly in the inactive GDP-bound form (D-Ras), whereas oncogenic Ras remains constitutively in the active GTP-bound form (T-Ras). NF1 is a tumor suppressor of 2818 amino acids whose disruption or deletion causes brain tumors called neurofibromatosis type 1 by elevating the T-Ras level. T-Ras activates several distinct oncogenic effectors, including Ser/Thr kinase Raf, GAP1, P1-3 kinase, PKC-zeta and Ra1 GDS. Interestingly, the binding of T-Ras to either GAPs or these oncogenic effectors requires the same effector domain I (residues 32-40) of T-Ras molecule. In other words, these GAPs and effectors compete for binding to T-Ras. Using a series of N- and C-terminal deletion mutants of NF1, we identified a 78 amino acid fragment (NF78, residues 1441-1518) as the minimum GAP domain, and a 56 amino acid fragment (NF 56, residues 1441-1496) as the minimum Ras-binding domain. Furthermore, we identified the Raf fragment of 81 amino acids (Raf81, residues, 51-131) as the minimum Ras-binding domain with a high affinity. We found that (i) these NF1 fragments and Raf81 compete for binding to T-Ras, and that (ii) over-expression of these NF1 or Raf fragments strongly suppresses the malignant transformation caused by oncogenic Ras mutants. Thus, these agents offer a unique opportunity to control the proliferation of T-Ras-associated tumors that represent more than 30% of all human carcinomas including neurofibromatosis type 1.

Animals↗
PubMed1998

Multiple bilateral thoracic meningoceles without neurofibromatosis: a case report.

Lateral thoracic meningoceles are rare and, in most cases, they are associated with neurofibromatosis. We report a case in which computerized tomography (CT)-myelography established the diagnosis of multiple, bilateral, lateral, thoracic meningoceles without neurofibromatosis. Plain film radiographs are necessary to evaluate any associated kyphoscoliosis and its progression. CT and magnetic resonance imaging demonstrate the extent of bony erosion, and the size and number of lateral thoracic meningoceles. CT-myelography reveals contrast medium in the meningoceles and is the major diagnostic imaging modality.

Humans↗
PubMed1998

Two novel mutations in exons 19a and 20 and a BsaBI [correction of BsaI] polymorphism in a newly characterized intron of the neurofibromatosis type 1 gene.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder. It is caused by mutations in the NF1 gene, which comprises 60 exons and is located on chromosome 17q11.2. A total of 170 unrelated NF1 patients were screened for mutations in four exons by temperature-gradient gel electrophoresis. Preparatory work revealed the presence of a previously uncharacterized intron (19a) in what was previously designated exon 19; this allowed us to develop assays for genomic mutation screening in the newly defined exons 19a and 19b. Two novel NF1 mutations were detected: a single-base insertion in exon 19a creating a frameshift, and a second mutation affecting the splice donor site of intron 20 and leading to skipping of exon 20. A novel BsaBI polymorphism was identified in intron 19a.

Adult↗
PubMed1998

Magnetic resonance imaging lesion analysis in neurofibromatosis type 1.

OBJECTIVE: To define the evolution of identified high-signal brain parenchymal lesions on magnetic resonance imaging (MRI) studies in patients with neurofibromatosis type 1 (NF-1). DESIGN: A cohort of patients with NF-1 who underwent MRI were identified prospectively and their imaging studies analyzed. PATIENTS: All referred patients with NF-1 (as defined by National Institutes of Health consensus criteria), who had undergone imaging with MRI were eligible. Of 123 patients with NF-1 whose conditions were evaluated, 30 patients had undergone 59 MRIs. There were 22 males and 8 females, aged 1 to 53 years with mean age of 12.5 years. Two groups of patients were identified, those with brain lesions (WBL) and those with no brain lesions. All initial and subsequently obtained MRIs from the WBL group were analyzed and tallied for number, size, and location of lesions over serial studies. RESULTS: Of the 19 patients with WBL, lesions were in hemispheres in 19 patients, and in the brainstem and the cerebellum in 10 patients each, respectively. Lesions were located in the cerebellum and globus pallidus most often (87 of 129 lesions). Of the patients with WBL having serial studies, a total of 97 lesions equaling 197 units (mean, 2.03 units per lesion) were identified at initial study. Follow-up evaluation (interval, 0.5-4.5 years; mean, 2.3 years), showed a decrease in both total number of lesions (68 [-29%]) and size (132 units; mean, 1.86 units per lesion [-33%]). Importantly, brainstem lesions increased in both number (+36%) and size (+6.4%) over the same intervals in 7 of 13 patients with WBL studied serially, whereas hemispheric and cerebellar lesions were more evanescent. CONCLUSIONS: High-signal T2 lesions on MRI in patients with NF-1 evolve over time. The evolution of the NF-1 lesion is region specific and may relate to preferential region-specific effects of the NF-1 gene product.

Adolescent↗
PubMed1999

Brain morphometric analysis in neurofibromatosis 1.

RATIONALE AND OBJECTIVES: To investigate the relationships between brain and skull base growth in patients with neurofibromatosis 1 (NF1) compared with healthy control subjects using brain magnetic resonance imaging (MRI) for morphometric analysis. METHODS: Evaluated patients included children who underwent T1- and T2-weighted or dual-echo proton density axial and T1-weighted sagittal brain MRI from January 1, 1988, to December 31, 1995. Study subjects (n = 27) received a diagnosis of NF1 by accepted National Institutes of Health clinical criteria and were compared with an age- and sex-matched control group (n = 43). Twenty-four predetermined ventricular and brain parenchymal dimensions and area calculations were evaluated. Data were analyzed using 2-tailed t tests, chi2 analysis, analysis of variance, and analysis of covariance adjusted for age and sex. Correlational analyses with respect to subject type and age were performed separately. RESULTS: There were 27 patients (20 boys, aged 1.0-17.7 years; mean age, 8.8 years) and 43 controls (22 boys, aged 0.1-17.7 years; mean age, 5.9 years). The mean ages between groups (boys, girls, and totals) were not statistically different. Significant differences were appreciated for 6 of 24 measures. Patients with NF1 had a significantly larger bicaudate width (P = .002), biatrial width (P<.001), and biparietal diameter (P = .003), but not hemispheric length. They also had significantly increased iter measures (P = .004), descending sigmoid sinus (P<.001), and an age-specific increase in brainstem height (P = .03) not seen in controls. CONCLUSIONS: Patients with NF1 experience dynamic changes in brain morphometry, resulting in a predominant lateral volume expansion of the supratentorial compartment and an increasing velocity of brainstem growth as they age. These data underscore brain-region-specific parenchymal overgrowth potential.

Adolescent↗