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We report a case of life-threatening hemothorax caused by rupture of a left thyrocervical trunk aneurysm and arteriovenous fistula in a patient with type I neurofibromatosis. This lesion was treated with endovascular coil embolization.
To understand the molecular mechanism of gastric tumorigenesis, the status of neurofibromatosis type 1 (NF1) gene was analyzed in human gastric cancer cell lines. Although the sequencing of the GTPase activating protein (GAP)-related region of NF1 (NF1-GRD) revealed no apparent mutation, the NF1-GRD transcript (type I) and that containing an additional 63 bp insert in the center of NF1-GRD (type II) were equally expressed in most gastric cancer cells. By contrast, type II was predominantly expressed in normal stomach mucosa. When these two types of NF1-GRD were bacterially expressed and their GAP activities were tested, both types of NF1-GRD similarly stimulated ras GTPase activity. However, arachidonic acid inhibited GAP activities of two types of NF1-GRD to different extents. These results suggest that the increased expression of type I NF1 protein may modulate ras-related signal transduction and it may be related to the control of the gastric cellular proliferation.
Glial mitogenic effect was investigated in sera from the following groups of subjects: group (1) 31 patients clinically and genetically affected by Neurofibromatosis type 1 (NF1) belonging to different families; group (2) 42 patients without family history of NF1 affected by sporadic neoplasms of the same histogenetic origin as the proliferative lesions that are present in NF1; group (3) 51 healthy volunteers without family history of NF1 nor of neoplastic disease; group (4) 54 clinically healthy relatives of the NF1 patients included in the first group. All NF1 patients and 3/54 healthy relatives had alterations of exons 31 or 32 of NF1 gene. Glial proliferation, measured by [3H]thymidine incorporation, was significantly increased by sera from all NF1 patients and from 23/54 of clinically healthy relatives, as compared to sera from healthy volunteers. This serum mitogenic activity strongly suggests the existence of soluble glial proliferating molecules in NF1 families. The molecular weight (3-30 kDa), the heat- and freeze-stability and the specificity for glial cells, suggest that the molecules responsible for this mitogenic effect are different from the growth factors previously described in NF1-associated tumor extracts and from lymphokines. Within each NF1 family, the maximal serum dilution stimulating glial proliferation was similar both in affected members and in their clinically healthy relatives. Since none of the clinically healthy relatives showing serum mitogenic activity was positive for the NF1 mutation analysis and, conversely, those having altered exons 31 or 32 of NF1 gene did not show any mitogenic activity; these results suggest that the phenotype expression of NF1 might depend not only on the NF1 mutations per se, but also on other genetic or epigenetic factors, such as serum glial proliferating molecules.
Three cases of neurofibromatosis are reported showing a wide spectrum of roentgen abnormalities affecting the skull and facial bones. One case had macrocrania and multiple calvarial defects; enlargement of the sella turcica and middle cranial fossa was also present. All the three cases had orbital changes either in the form of enlargement, reduced anteroposterior width or loss of bony outlines with an appearance of emptiness. The other two cases showed predominantly facial involvement with hypoplasia of the mandibular body and ramus, abnormal coronoid process, zygomatic arch, hypoplastic maxilla, cystic mandible with abnormal dentition and absence of the osseous external auditory meatus. Intra-orbital calcification was present in one case. The radiological projections required to evaluate such cases are discussed. The 20 degrees occipito-mental view has been found extremely useful and is recommended.
A 26-year-old man who had neurofibromatosis type-2 with symptoms of unexplained optic disc edema is reported. Magnetic resonance imaging (MRI) revealed bilateral acoustic schwannomas. Obstructive hydrocephalus, however, was not evident in spite of his severe disc edema and visual loss. After partial removal of the right acoustic schwannoma, symptoms of intracranial hypertension, such as vomiting and headache, developed and MRI demonstrated evidence of obstructive hydrocephalus. Placement of a ventricular-peritoneal shunt relieved the symptoms of intracranial hypertension, but visual acuity in his left eye was reduced to hand motion due to secondary optic atrophy. In patients with similar symptoms it is suggested that, in addition to tumor removal, early treatment to decrease intracranial pressure should be considered when visual function is progressively impaired by the symptoms of prolonged papilledema.
A child is reported who developed partial colonic obstruction from an intussuscepting polypoid mass in the transverse colon. A 5 cm plexiform ganglioneurofibroma was found at laparotomy. Examination of the entire gastrointestinal tract revealed no other neurogenic tumors. Gastrointestinal involvement by neurofibromatosis in children is rare; however, children with von Recklinghausen's disease who complain of vague abdominal symptoms should be evaluated for gastrointestinal tumors.
Visuospatial deficits have been reported in patients with neurofibromatosis type 1 (NF 1), although detailed observations regarding academic achievement are conflicting. Using neurocognitive testing and magnetic resonance imaging, we studied 12 families, each comprising one child with NF 1, an unaffected sibling of the same age range (6 to 16 years), and both biologic parents. The Full Scale IQ ranged from 70 to 130 among children with NF 1 and from 99 to 139 among unaffected siblings. A significant (p < 0.01) pairwise difference was found between each child with NF 1 and sibling on the Full Scale IQ and the Verbal IQ. On a single visuospatial test, Judgement of Line Orientation, children with NF 1 did significantly worse than siblings (p < 0.01). Children with NF 1 had significant learning disabilities in written language and reading (p < 0.05) and in neuromotor dysfunction (p < 0.005) compared with siblings. A significant correlation was found between the pairwise lowering of the Full Scale IQ and Judgment of Line Orientation scores in children with NF 1 and the number of locations in which, on magnetic resonance imaging, T2-weighted hyperintensities were seen (Full Scale IQ: p < 0.0003; Judgment of Line Orientation score: p < 0.02). We conclude that NF 1 is associated with a significantly lower Full Scale IQ, multifocal cognitive deficits (Verbal IQ, Judgment of Line Orientation score), reading disability, and neuromotor deficit. Pairwise cognitive differences correlated with the number of brain lesions on magnetic resonance imaging.
Twelve new cases of childhood leukemia and neurofibromatosis were ascertained and evaluated in conjunction with 17 previously well-documented cases. The ratio of ALL:nonlymphocytic leukemia was 9:20, markedly different from the 4:1 ratio in children without NF. Rarer subtypes predominated: 8 CML and 8 AMML. The peculiar distribution of leukemia by cell type and the number of cases observed in the United States indicate that the risk of childhood leukemia in NF is increased. Two possible variants were noted: NF with "transient leukemia," and multiple skin xanthomas with nonlymphocytic leukemia.
To assess the natural history of optic pathway tumors (OPT) in children with neurofibromatosis type 1 (NF-1), from January 1985 through May 1993 we performed a prospective, longitudinal study of OPT in an unselected population of children with NF-1. Of 227 children with NF-1 seen in a specialty clinic, 176 (77%) underwent neuroimaging. Children in whom tumors were identified were followed closely by both repeated neuroimaging and ophthalmologic examinations to detect tumor growth or visual deterioration. Thirty-three children (19%) were found to have OPT at a median age of 4.2 years. The median age of children who had ophthalmologic complaints was significantly lower than that of children who had no such complaints (1.9 vs 5.3 years; p < 0.001). Although eight tumors were discovered because of ophthalmologic complaints or evidence of precocious puberty, 25 children (76%) were free of symptoms at the time of diagnosis. Twenty-one children (64%) had normal ophthalmologic findings at diagnosis; six children, all with chiasmal tumors, had previously unrecognized decreased visual acuity. Only three children (9%) had evidence of either tumor growth or deteriorating vision after diagnosis; the median duration of neuroimaging follow-up was 2.4 years (range, 0.2 to 7.2 years) and of ophthalmologic examinations 3.4 years (range, 0.2 to 8.1 years). All symptomatic OPT were diagnosed before 6 years of age. We conclude that OPT rarely progress during the next few years in children with NF-1 once the OPT have been discovered. The utility of screening neuroimaging for OPT in symptom-free children with NF-1 appears very limited.
OBJECTIVE: To distinguish the clinical manifestations and natural history of optic pathway tumors (OPT) associated with neurofibromatosis type 1 (NF-1 OPT) from that of OPT not associated with NF-1 (non-NF-1 OPT). METHODS: Two groups of children with OPT were compared: (1) 17 children with NF-1 OPT who were followed prospectively, and (2) 19 children with non-NF-1 OPT who were identified retrospectively by a review of medical records. RESULTS: Precocious puberty was a common initial sign in the children with NF-1 OPT (5/17), and was not found in any patients without NF-1. In contrast, children with non-NF-1 OPT had symptoms attributable to increased intracranial pressure (12/19 and nystagmus (5/19); these symptoms were not found in any patient with NF-1. Decreased visual acuity at the time of diagnosis was common in both groups. There was no significant difference between the children with NF-1 OPT and those with non-NF-1 OPT as to age at diagnosis or sex distribution. Optic nerve involvement was more common in NF-1 (p < 0.001). Both isolated and bilateral optic nerve tumors were found exclusively in children with NF-1, whereas chiasmal (p = 0.016) and optic tract involvement (p = 0.001) were more common in those with non-NF-1 OPT. Radiographic evidence of hydrocephalus was found in none of the children with NF-1 OPT compared with 79% of the non-NF-1 OPT group. Progressive disease was seen in 12% of patients with NF-1 OPT compared with 63% of those with non-NF-1 OPT. CONCLUSIONS: Differences exist between NF-1 OPT and non-NF-1 OPT both at the time of diagnosis and during follow-up. Optic pathway tumors caused by NF-1 and non-NF-1 OPT have different biologic properties that distinguish both their initial clinical manifestations and their natural history.
We undertook a comprehensive study of children with neurofibromatosis type 1 (NF-1) cared for in a large multidisciplinary clinic to determine the prevalence of precocious puberty and its relationship to optic pathway tumors (OPTs). Precocious puberty was diagnosed in 7 of 219 children with NF-1 (5 boys and 2 girls) examined between Jan. 1, 1985, and April 20, 1993. All seven children had OPTs involving the optic chiasm; they represented 39% of children with NF-1 and chiasmal tumors (95% confidence interval, 17% to 64%). Eleven prepubertal children (aged 2 to 10 years) with NF-1 and OPTs, and age- and sex-matched NF-1 control subjects without OPTs, underwent luteinizing hormone-releasing hormone (LH-RH) stimulation tests. Two boys with OPTs had pubertal luteinizing hormone (LH) responses, and testosterone levels > 10 ng/dl. Basal LH levels were also elevated in these two boys when tested with a very sensitive immunochemiluminometric assay. None of the children without an OPT had either a pubertal response to LH-RH or an elevated basal LH level. We conclude that precocious puberty in children with NF-1 is found exclusively in those who have OPTs involving the optic chiasm; it is a common complication in those children. With the use of a highly sensitive LH assay, biochemical evidence of hypothalamic-pituitary-gonadal axis activation may be demonstrated, even without provocative testing.
A girl aged 5 years and a boy aged 8 years with neurofibromatosis type I had clinical and biochemical evidence of central precocious puberty. Magnetic resonance imaging on two occasions in each patient failed to demonstrate any abnormality of the optic tracts or optic chiasm.
OBJECTIVE: To describe social and emotional problems in children and adolescents with neurofibromatosis type 1 (NF1) and propose interventions. Our hypothesis is that children with NF1 will have significantly more social and emotional problems, compared with their unaffected siblings and children in the general population. STUDY DESIGN: Forty-three children with NF1 and 22 unaffected siblings (ages 5 to 18 years) were assessed with a standardized test completed by parents and teachers (the Child Behavior Checklist). RESULTS: As with other aspects of NF1, there was variable expressivity. However, when rated by parents, children with NF1 had significantly more problems in comparison with test norms or unaffected siblings on 7 of 8 scales: Social Problems, Attention Problems, Anxiety/Depression, Withdrawal, Thought Problems, Somatic Complaints, and Aggressive Behavior. Children with NF1 also scored lower than unaffected siblings on measures assessing sports and other activities. Teachers reported fewer differences. CONCLUSIONS: We propose interventions in the form of information for parents; early screening and treatment for speech, motor, and cognitive problems; and an increased level of intervention to prevent and treat psychologic problems, including systematic screening with standardized tests.
The impact of neurofibromatosis type 1 (NF1) on psychiatric symptoms and diagnoses, personality variables and self evaluation was studied in a 12 year-follow-up of patients with NF 1 in the city of Göteborg, Sweden. 48 living adult patients with NF1 were re-evaluated in 1990 in a 12 year long time follow up study. The patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders. The following scales were used; the Comprehensive Psychopathological Rating Scale (CPRS), the Karolinska Scales of Personality inventory (KSP) and the Self-Evaluation Scale (SES). A significant psychopathology was found in the NFI patients, p <0.001. One third of the patients were affected by a psychiatric disease, 21% by dysthymia. There was no significant progress in psychiatric symptoms in the follow up period. The personality profile disclosed a heightened self-esteem. The chronic stigmatizing character of NF1 may be the reason for the increased psychopathology found.
We report a 18-year-old man who developed slowly progressing right drop foot. Bilateral acoustic neurinoma was found and he was diagnosed as neurofibromatosis-2. Right sural nerve biopsy showed multiple small onion-bulb-like structures in the nerve fascicle. Electronmicroscopic and immunohistochemical studies on this structure confirmed cytological characteristics of Schwann cells, while previous reports suggest that this structure originates from perineural cells. The present report is the first to show both ultrastructurally and immunohistochemically that the onion-bulb-like structure is derived from Schwann cell.
A solitary neurofibroma of the urinary tract is rare. More rare in the urinary tract are neurofibromas associated with the neurofibromatosis of Von Recklinghausen's disease. A case of multiple neurofibromas of the bladder degenerating into neurofibrosarcoma is described.
We report a case of clitoral involvement by neurofibromatosis in which the clitoris resembled a phallus. The patient was treated successfully by clitoroplasty. This is the seventh such case reported in the English literature.
Neurofibromatosis type 1 (NF1) is among the most common human genetic disorders, having a constellation of cutaneous and skeletal manifestations, intellectual impairment, and an increased risk for a variety of malignancies. The NF1 gene has a high spontaneous mutation rate and is also associated with a variety of sporadic cancers in the general population. While a number of laboratories are involved in a coordinated effort to identify NF1 mutations, an important gap in our knowledge is an understanding of the mechanisms responsible for NF1 mutagenesis. In this present paper we describe our analysis of the sequence environment in the NF1 gene at those sites where small deletions, insertions and nucleotide substitution mutations have been reported. Our objective was to determine whether specific nucleotide sequences commonly occur at these mutation sites within the NF1 gene. We assessed how frequently independent NF1 mutations occur at the site of short direct repeats, single nucleotide repeats (homonucleotides) and at CpG and CpNpG motifs. We have established that homonucleotide and short direct repeats are commonly involved in the majority of small deletions and insertions analysed. Substitution mutations are frequently associated with homonucleotide repeats and methylatable CpG dinucleotides and CpNpG trinucleotides. We suggest that NF1 mutations are acquired and retained by cells through an intricate balancing of repair and replication mechanisms. Such mutations may provide a proliferative advantage for that cell and its progeny.