1/151. A case of laryngeal neurinoma with neurofibromatosis 2. We present a case of a laryngeal neurinoma in a patient with neurofibromatosis 2. A 39-year-old man presented to our hospital with multiple complaints including progressive bilateral hearing loss, dizziness, dyspnea, dysphagia, and a 9-year history of right lower leg weakness. magnetic resonance imaging demonstrated multiple lesions including bilateral cerebellopontine angle tumors, a foremen magnum tumor, multiple tumors of the spinal cord, a laryngeal tumor, and several retrocervical tumors. Fiberoptic laryngoscopy revealed a large submucosal supraglottic tumor. The laryngeal tumor was visualized through microlaryngoscopy and excised with a KTP laser directed through a quartz fiber. ( info) |
| Gangliogliomas of the spinal cord are rare disease entities that occur in early childhood. Their occurrence in association with neurofibromatosis Type 2 (NF2) has not been described. The authors describe the unique case of a 2-year-old child with stigmata of NF2 who harbored a spinal cord ganglioglioma that presented as a rapidly growing, exophytic intramedullary mass lesion at the cervicomedullary junction. Treatment consisted of complete surgical resection. Histopathological analysis of the lesion demonstrated a mixed population of neoplastic cells, of both neuronal and glial lineage, that supported the diagnosis of ganglioglioma. ( info) |
3/151. Bilateral facial nerve schwannomas. facial nerve schwannoma is an uncommon tumor and bilateral facial nerve tumors are extremely rare. A case is presented in which neuromas affecting the intra-canalicular and labyrinthine portions of both facial nerves occurred. Radiologic assessment demonstrated the origin of these tumors. Eventual tumor involvement of the sole functioning cochlea resulted in the development of total hearing loss. Management entailed symptomatic care and surgical resection. Auditory rehabilitation was attempted using cochlear implantation, but results have not been satisfactory. Genetic screening identified a mutation in the NF2 gene. It is proposed that this patient's condition should be considered a variant of neurofibromatosis 2 and that bilateral facial neuromas should be included in the clinical criteria for this condition. ( info) |
4/151. Neurofibromatosis type 2 with multiple primary brain tumors in monozygotic twins. BACKGROUND: Although monozygotic twins with neurofibromatosis complicated by brain tumors rarely have been reported, none of them fulfilled the diagnostic criteria for neurofibromatosis type 2 (NF2). METHOD: We describe here the first pair of monozygotic twins with NF2, and the result of the molecular analysis of their NF2 gene. RESULTS: One of the brothers (Case 1) developed tetraparesis and cerebellar truncal ataxia at age 12. He had no skin lesions. Radiological examinations revealed, at one time or another, bilateral vestibular schwannomas, a foramen magnum meningioma, five supratentorial meningiomas, and multiple spinal cord tumors. He underwent three operations over a 10-year period to remove tumors. The patient is now 23 years old and is in college. Although asymptomatic when examined at age 12, CT scan revealed that his brother (Case 2) also had multiple brain tumors, including meningiomas, schwannomas, and multiple spinal tumors. Tumors were removed in eight operations over a 10-year period. The patient is now deaf and confined to a wheelchair. An identical nonsense mutation caused by a C to T transition (C169) in a CpG dinucleotide of the NF2 gene was identified in both patients. CONCLUSION: These results led us to speculate that dissimilarities with respect to time of appearance, distribution, and extent of symptoms and tumors between the twins were dependent on the influence of other genetic factors. ( info) |
5/151. Severe phenotype of neurofibromatosis type 2 in a patient with a 7.4-MB constitutional deletion on chromosome 22: possible localization of a neurofibromatosis type 2 modifier gene? Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder predisposing to multiple neoplastic lesions with the hallmark of schwannoma arising at the eighth cranial nerve. NF2 shows a distinct clinical variability, with a mild and a severe form of the disease. The NF2 gene is mutated in constitutional dna of affected patients from NF2 families and in sporadic cases. Comprehensive mutation analyses in patients with severe and mild phenotypes revealed mutations in only 34%-66%. In the remaining fraction, the genetic mechanism behind the development of NF2 is unknown. Analyses of germline mutations do not provide a conclusive explanation for the observed clinical heterogeneity of NF2. It can therefore be hypothesized that other factors, e.g., modifier gene(s), contribute to the development of a more severe NF2 phenotype. We report a mentally retarded patient with the severe form of NF2 who displays a 7.4 million base pair deletion on chromosome 22. We performed a full genetic characterization of this case using heterozygozity analysis of 41 markers from chromosome 22, detailed FISH mapping of deletion breakpoints, allelotyping of all other chromosomes, and sequencing of the NF2 gene in tumor dna. Two genomically large deletions similar in size (700-800 kb), which encompass the entire NF2 gene, have been reported previously in mildly affected NF2 patients. The centromeric breakpoints of these deletions were similar to the centromeric breakpoint in the present case. However, the deletion in our patient extends over a much larger distance toward the telomere of 22q. Our results support the existence of NF2 modifier gene(s) and suggest that such a putative locus maps to a 6.5-MB interval on 22q, between D22S32 and the MB gene. ( info) |
| cochlear implantation has a limited but definite role in the rehabilitation of certain neurofibromatosis type 2 (NF2) patients. The presence of a dead ear either before, or after, tumour removal does not necessarily imply loss of function in the eighth nerve; in some instances the hearing loss will be cochlear. Promontory or round window electrical stimulation may help to identify those individuals with surviving eighth nerve function. In such patients multichannel cochlear implantation promises a better level of audition than the auditory brain stem implant. This paper highlights such a case and the management problems are discussed. ( info) |
7/151. meningioma with meningioangiomatosis: a condition mimicking invasive meningiomas in children and young adults: report of two cases and review of the literature. Meningioangiomatosis is a malformative meningovascular proliferation that occurs sporadically and in patients with neurofibromatosis type 2. Its histologic features of perivascular proliferation of elongated fibroblast and meningothelial cells trapping islands of gliotic cortex may be erroneously interpreted as invasion when an overlying meningioma is present. We report two cases of meningioangiomatosis associated with meningioma and review the literature on the subject for a total of six cases. The age of patients ranged from 9 months to 33 years. All cases were single lesions, and none had clinical evidence of neurofibromatosis type 2. Meningiomas in children have been regarded as having more aggressive behavior than their adult counterparts, with more frequent invasion of the underlying brain. The lack of correlation between brain invasion and recurrence observed in series of meningiomas in young patients may suggest that some of these lesions are meningioangiomatosis associated with meningioma rather than invasive meningiomas. ( info) |
8/151. association of lower cranial nerve schwannoma with spinal ependymoma in ? NF2. A 15 year old male, who had earlier been operated for intraspinal intramedullary ependymoma, subsequently developed a right cerebello pontine (CP) angle mass. A diagnosis of right CP angle ependymoma was considered, in view of established histology of previously operated spinal lesion. Histopathological examination of the well defined extra-axial mass, which was attached with ninth cranial nerve, however revealed a schwannoma. A diagnosis of Neurofibromatosis-2 (NF2) is strongly suspected, because of well established fact, that the spinal ependymomas may have association with lower cranial nerve schwannomas in NF2. Cranial and spinal MRI screening for early diagnosis of associated, asymptomatic lesions, in suspected cases of NF2, particularly in children, is recommended. ( info) |
9/151. Selective B-wave reduction with congenital cataract in neurofibromatosis-2. OBJECTIVE: To electroretinographically evaluate a case of neurofibromatosis-2 (NF-2). DESIGN: Case report and literature review. PARTICIPANT: A 29-year-old man diagnosed with NF-2. MAIN OUTCOME MEASURES: electroretinography (ERG), ophthalmic biomicroscopy, and ultrasound examination results were reviewed. RESULTS: The ERG of one eye showed selective reduction of b-wave amplitudes. A characteristic posterior subcapsular lens opacity also was observed in that eye. A dense white congenital cataract and a retinal detachment were detected in the fellow eye. CONCLUSIONS: An inner retinal dysfunction, as evidenced by an abnormal ERG, may occur in NF-2. Further ERG evaluation of other patients with NF-2 is indicated to determine possible associations between NF-2 and selective b-wave reduction. ( info) |
10/151. The magnetless Clarion cochlear implant in a patient with neurofibromatosis 2. We present our experience using the Clarion magnetless multichannel cochlear implant with a woman profoundly deafened following bilateral acoustic neuromata as a consequence of neurofibromatosis 2 (NF2). The right neuroma had been previously removed without an attempt at neural preservation. On the left, however, a posterior fossa approach had been taken with the aim of preserving hearing. Although the left cochlear nerve appeared to be undamaged at the end of the operation, no hearing thresholds could be elicited on post-operative audiometry, because of damage either to the cochlear nerve or to the blood supply to the cochlea. Round window electrical stimulation subsequently produced a perception of sound, confirming that the cochlear nerve was capable of functioning and that a cochlear implant would be effective. Because she would need regular magnetic resonance imaging (MRI) to monitor existing and future NF2 lesions, it was decided to use a magnetless Clarion implant, which has been shown to be MRI compatible. We report our experience of using the device in this case and discuss some of the issues related to the provision of cochlear implants to patients with NF2. ( info) |