1/156. Microvascular reconstruction of the skull base: indications and procedures.PURPOSE: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. patients AND methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. RESULTS: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. CONCLUSIONS: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
2/156. Cerebral B-cell lymphoma following treatment for tolosa-hunt syndrome.We herein report a unique case of cerebral lymphoma which occurred after lymphocytic neuritis of cranial nerves causing tolosa-hunt syndrome and demonstrate the histological difference between these two diseases. A 70-year-old woman developed a sensory disturbance in the first and third divisions of the left trigeminal nerve and a left ocular movement disturbance five years before death. Although she was clinically diagnosed to have a schwannoma in the left cavernous sinus, a histologic examination verified a diffuse infiltration of T lymphocytes in the left trigeminal ganglion. Corticosteroid therapy was effective. Thereafter she demonstrated a disturbance of consciousness and dysphasia four years after surgery. A T1-weighted magnetic resonance image (MRI) disclosed high intensity lesions in both the basal ganglia and corpus callosum. She also showed progressive spastic paralysis. At autopsy a diagnosis of primary intracranial B-cell lymphoma was made. Although there was no invasion of the lymphoma cells into the left trigeminal nerves, a mild inflammatory infiltration of T cells still remained.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
3/156. 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.- - - - - - - - - - ranking = 2.1802775561718keywords = schwannoma, vestibular schwannoma (Clic here for more details about this article) |
4/156. Solitary olfactory groove schwannoma: case report with review of the literature.A 45-year-old man presented with headaches of 6 months' duration and generalized seizures in a cluster 2 days prior to admission. Examination revealed bilateral papilloedema and no focal deficits. CT scan showed an isodense enhancing mass lesion in the right frontobasal region with perilesional edema. Bifrontal craniotomy (with total excision of the tumor) revealed a tumor in the region of the right olfactory groove attached to the cribriform plate. Histopathological examination disclosed it to be a hyalinised schwannoma. Solitary schwannomas arising from the olfactory groove are extremely rare. Only six other cases have been reported so far. The presentation. CT scan findings and histogenesis of the tumor are discussed along with a review of the literature.- - - - - - - - - - ranking = 6keywords = schwannoma (Clic here for more details about this article) |
5/156. Pineal ganglioneuroblastoma in an adult.A 57-year-old male with pineal ganglioneuroblastoma was reported. The tumor was composed of a predominant ganglioneuromatous component and a small neuroblastic component. Primary ganglioneuroblastoma of the pineal region is extremely rare. To our knowledge, only three cases have been documented. This case may have a good prognosis because there is a predominant ganglioneuromatous component defined by both neurofilament triplet proteins and synaptophysin. The clinical significance of the neuronal differentiation in the present case and pathological considerations are discussed.- - - - - - - - - - ranking = 0.055243556812579keywords = neuroma (Clic here for more details about this article) |
6/156. facial nerve schwannoma in the cerebellopontine cistern. Findings on high resolution CT and MR cisternography.We report a case of facial nerve schwannoma originating in the cerebellopontine cistern, diagnosed by cochlear sensorineural hearing loss, and involvement in the facial nerve canal and the anterior epitympanic recess. Precise analyses of neuro-otological and neuroradiological studies are crucial to obtain an accurate preoperative diagnosis.- - - - - - - - - - ranking = 5keywords = schwannoma (Clic here for more details about this article) |
7/156. Multiple intracranial lipomas, hypogenetic corpus callosum and vestibular schwannoma: an unusual spectrum of MR findings in a patient.We describe imaging findings of a patient with multiple intracranial lipomas, hypogenetic corpus callosum and a vestibular schwannoma. We did not find association of intracranial lipomas and vestibular schwannoma in English literature.- - - - - - - - - - ranking = 7.0816653370309keywords = schwannoma, vestibular schwannoma (Clic here for more details about this article) |
8/156. Malignant schwannoma metastasizing to the parenchyma of the brain--case report.A 48-year-old male presented with a very rare case of malignant schwannoma metastasizing to the parenchyma of the brain. He had undergone previous radical surgical resection of an abdominal wall tumor that was histologically confirmed as a malignant schwannoma. Five years later, the patient presented with metastases to the parenchyma of the brain and lung. A large mass at the left frontoparietal region was totally resected immediately after intratumoral hemorrhage. He recovered well and the lung metastasis was also removed, but he later developed further multiple metastases in the lung and brain.- - - - - - - - - - ranking = 6keywords = schwannoma (Clic here for more details about this article) |
9/156. Intracranial sarcoma in a patient with neurofibromatosis type 2 treated with gamma knife radiosurgery for vestibular schwannoma.OBJECTIVE: To discuss the possible relationship between stereotactic radiation therapy and the development of a meningosarcoma. STUDY DESIGN: Retrospective case review. PATIENT: A 19-year-old woman with bilateral vestibular schwannomas (neurofibromatosis type 2). One large tumor was removed totally by the translabyrinthine approach; the other smaller tumor was treated with stereotactic radiation (SRT). Six years after SRT, a malignant tumor (meningosarcoma) developed at the exact site of radiation. The patient subsequently died of this tumor. OUTCOME MEASURE: On the basis of literature surveys, the possibility and risk of postirradiation neoplasia after SRT is discussed. Furthermore, the possible causal association between SRT and the development of the meningosarcoma in this case is evaluated. CONCLUSION: On the basis of statistical considerations, the development of the reported mesenchymal sarcoma was most likely caused by the stereotactic radiation therapy.- - - - - - - - - - ranking = 5.9013877808591keywords = schwannoma, vestibular schwannoma (Clic here for more details about this article) |
10/156. Analyses of proliferative potential in schwannomas.We report studies of schwannomas with a high percentage of MIB-1 positive cells. Thirty-eight specimens from 36 cases of schwannoma in the intracranial and spinal regions comprise the substance of this study. The MIB-1 positive cells were measured using immunohistochemical staining. In nine cases with a positivity index (PI) of 5% or more, immunohistochemical staining using dna topoisomerase IIalpha (topo-II) and CD68 was performed. In some cases, we also searched for apoptosis with the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method. Three of nine cases with 5% or more positive MIB-1 cells had a very high cellularity with mitotic figures and were considered cellular Schwannomas. Their MIB-1 PI values were 8.21%, 10.00%, and 21.37%. However, the remaining six cases showed little evidence of malignancy. Their PIs were comparatively low, ranging from 5.19% to 8.41%, and the positive findings were localized in many cases. In these cases, we examined the sites where MIB-1 was measured and found that they corresponded to the borderline site between Antoni type A and B patterns and tended to be associated with an infiltration of CD68-positive macrophage. Furthermore, apoptotic cells appeared in the sites. With topo-II staining, the PIs in the same sites of these six cases were low, ranging from 0.78% to 1.93%. This implies that the high MIB-1 PI that was seen in these six cases was caused by reaction of MIB-1 to tumor cells that brought about an abnormality in the cell cycle by degeneration, such as apoptosis. In the site of formation of Antoni type B, MIB-1 may be a false positive in tumors with degenerative findings such as schwannomas. Topo-II was useful in these cases.- - - - - - - - - - ranking = 7keywords = schwannoma (Clic here for more details about this article) |
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