1/61. Biologic heterogeneity of angiomatous meningiomas.Three angiomatous meningiomas, classified histologically as benign, were analyzed cytogenetically and examined for the expression of EGF/PDGF and their receptors by immunohistochemistry. An accumulation of p53 protein and the presence of mutations in exons 5-8 of the p53 gene in neoplastic cells were also determined. In one tumour, chromosome studies revealed near diploid karyotype with the loss of chromosome 22. Two other meningiomas revealed tetraploid karyotypes with the presence of telomeric associations and a wide spectrum of numerical, complex chromosome aberrations. Moderate EGF and EGFR immunoreactivity was found in three and one meningioma, respectively. All tumours exhibited diffuse PDGF and PDGFR-beta expression. No p53 gene mutations were found, but one tumour expressed strong and dispersed p53 immunopositivity. This findings reflect the biological heterogeneity of angiomatous meningiomas.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
2/61. Meningotheliomatous meningioma accompanied by aspergillosis at the skull base.A 73-year-old man was admitted because of right frontal headache and gradual loss of right visual acuity, which had been occurring for 1 year. He had been treated with corticosteroids under the diagnosis of retrobulbar optic neuritis at a nearby clinic. magnetic resonance imaging (MRI) revealed a nodular lesion at the tuberculum sellae, which showed isointensity on T1-weighted images, iso- to low-intensity on T2-weighted images, and heterogeneous enhancement with Gd-DTPA. meningioma was diagnosed, and surgery was performed but was limited to biopsy because of intraoperative detection of purulent inflammation of the nodule. Histologic examination revealed aspergillosis in a portion of the meningotheliomatous meningioma. The patient died of meningoencephalitis about 1 month after surgery in spite of extensive treatment with antifungal agents. MRI findings of meningioma and aspergillosis are similar, thus making preoperative diagnosis difficult. However, this case provides evidence that aspergillosis should be included in the differential diagnosis when a skull-base meningioma-like nodule is noted if sinusitis is revealed in the sphenoid sinus.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
3/61. Intraspinal osteogenic meningioma: report of a case.Dense calcification and psammomatous bodies are common in spinal meningioma, but are rarely reported in osteogenic meningioma. We present a 73-year-old woman with an extramedullary, intradural tumor located at the T5 vertebra. The tumor showed mixed intensity and heterogeneous enhancement on the T1-weighted image and hypointensity on the T2-weighted image, and was situated near the spinal nerve root. The tumor's initial symptom was myelopathy, as is usual with spinal meningioma. We successfully removed the tumor under microscopy and found it to be separated from the vertebral column by the epidural space. The symptoms and signs improved gradually after the operation. Because the pathologic examination revealed areas of lamellar bone with bone marrow in the transitional meningioma, and because these were not related to the psammomatous bodies, osteogenic meningioma was diagnosed. metaplasia of arachnoid cells is considered to be the putative etiology of osteogenic meningioma.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
4/61. Intraoperative validation of functional magnetic resonance imaging and cortical reorganization patterns in patients with brain tumors involving the primary motor cortex.OBJECT: The purpose of the present study was to compare the results of functional magnetic resonance (fMR) imaging with those of intraoperative cortical stimulation in patients who harbored tumors close to or involving the primary motor area and to assess the usefulness of fMR imaging in the objective evaluation of motor function as part of the surgical strategy in the treatment of these patients. methods: A total of 11 consecutive patients, whose tumors were close to or involving the central region, underwent presurgical blood oxygen level-dependent fMR imaging while performing a motor paradigm that required them to clench and spread their hands contra- and ipsilateral to the tumor. Statistical cross-correlation functional maps covering the primary and secondary motor cortical areas were generated and overlaid onto high-resolution anatomical MR images. Intraoperative electrical cortical stimulation was performed to validate the presurgical fMR imaging findings. In nine (82%) of 11 patients, the anatomical fMR imaging localization of motor areas could be verified by intraoperative electrical cortical stimulation. In seven patients two or more activation sites were demonstrated on fMR imaging, which were considered a consequence of reorganization phenomena of the motor cortex: contralateral primary motor area (nine patients), contralateral premotor area (four patients), ipsilateral primary motor area (two patients), and ipsilateral premotor area (four patients). CONCLUSIONS: Functional MR imaging can be used to perform objective evaluation of motor function and surgical planning in patients who harbor lesions near or involving the primary motor cortex. Correlation between fMR imaging findings and the results of direct electrical brain stimulation is high, although not 100%. Based on their study, the authors believe that cortical reorganization patterns of motor areas might explain the differences in motor function and the diversity of postoperative motor function among patients with central tumors.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
5/61. meningioma of the pituitary stalk without dural attachment: case report and review of the literature.OBJECTIVE AND IMPORTANCE: Tumors in the suprasellar region such as adenomas of the pituitary gland, craniopharyngiomas, nonneoplastic cystic lesions (especially Rathke's cleft cysts), and meningiomas are frequently encountered in neurosurgical practice. Meningiomas originate from the arachnoid layer connected to the dura of the anterior or posterior clinoidal process, or the tuberculum, dorsum, or diaphragma sellae. Tumors originating from the pituitary stalk are rare. Such lesions may include germinomas, astrocytomas, histiocytosis X, hamartomas, and sarcoidosis. We report a patient with a suprasellar meningioma originating from the pituitary stalk with no connection to the adjacent dura. CLINICAL PRESENTATION: A 50-year-old man was assessed for impotence and loss of libido. physical examination revealed no abnormalities. Endocrinological investigations disclosed nearly complete hypopituitarism, and magnetic resonance imaging revealed a suprasellar homogeneously enhancing tumor. INTERVENTION: Complete surgical resection was performed in an endoscope-assisted right-sided supraorbital craniotomy. The tumor originated from the pituitary stalk with no connection to the surrounding dura. The histopathological diagnosis was meningioma. CONCLUSION: Although meningiomas frequently occur in the suprasellar region, this patient with a suprasellar meningioma is unique because the tumor originated from the pituitary stalk with no connection to the surrounding dura. The absence of dural attachment has been described in 43 extracerebral meningiomas, but a suprasellar location has been reported only once previously. Recognition of this phenomenon is important, because meningiomas require a different therapeutic strategy than most other tumors of the pituitary stalk.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
6/61. Far lateral approach with intraoperative ultrasound Doppler identification of the vertebral artery.A 69-year-old woman presented with right hemiparesis and magnetic resonance imaging revealed a meningioma at the ventral aspect of the foramen magnum. We used a retromastoid curvilinear incision down the lateral aspect of the neck to expose the semispinalis and other muscles. Guided by ultrasound to avoid damage to the vertebral artery beneath the semispinalis, we incised the semispinalis muscle in a U-shape that hinged at the retromastoid curvilinear incision with its one limb along the border of the foramen magnum and the other limb along the posterior arch of the atlas. The other muscles were divided in line with the curvilinear incision and retracted posteriorly with the bulk of semispinalis to expose the bones, not disturbing the U-shaped piece of semispinalis that covered the vertebral artery. Similarly guided by ultrasound, we performed far lateral suboccipital craniectomy and laminectomy, exposed the dura above and below the dural entry of the vertebral artery, opened the dura cephalad and caudal to the dural entry of the vertebral artery, and excised the tumor. This method provided adequate exposure to the lateral aspect of the cranio-vertebral junction and minimized the risks of dissecting the whole extradural segment of vertebral artery. It requires more cases to determine whether the results of this patient can be generalized.- - - - - - - - - - ranking = 3keywords = near (Clic here for more details about this article) |
7/61. MRI appearances mimicking the dural tail sign: a report of two cases.We report two cases in which the MRI appearances mimicked the dural tail sign; a glioma extending into the subarachnoid space, and a meningioma extending to the subdural space. They indicate that tumour invasion into the subarachnoid or subdural space, should be considered when prominent linear enhancement is observed along the dura mater adjacent to tumours.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
8/61. Extended middle fossa surgery for meningiomas within or at the internal auditory canal.OBJECTIVE: To show the clinical outcome in patients with meningioma within or at the internal auditory canal (IAC) operated on by the extended middle cranial fossa approach. STUDY DESIGN: Retrospective case review. SETTING: A tertiary referral center. patients: Twelve patients, 9 women and 3 men, whose ages ranged from 37 to 70 years (mean 57 years). One tumor was entirely intracanalicular, 5 had an intra-extracanalicular growth, 3 were centered at the posterior porus lip, and 3 tumors were localized in the midpetrosal region with spread into the IAC. INTERVENTION: Extended middle cranial fossa approach. MAIN OUTCOME MEASURES: magnetic resonance imaging and computed tomography were used for follow-up and reevaluation of the operative sites. facial nerve function and hearing were examined. RESULTS: Complete resection was achieved in 10 (83%) of 12 patients. The retrosigmoid approach was necessary to complete tumor resection in one patient, and in another, partial resection was done because of the en plaque type of tumor growth. There was one unexpected recurrence. All patients retained normal or near-normal facial nerve function postoperatively. Three patients were deaf before surgery, and preoperative hearing level was preserved in 42%. CONCLUSIONS: Attempted hearing preservation surgery is justified in patients with small tumors and preserved hearing, because tumor exposure and safety of resection are comparable with that of hearing-destructive procedures. Lateral extension of the tumor to the fundus does not prevent complete resection with preservation of function, and elective bone resections beyond the visible tumor margins seem not to substantially influence the tumor recurrence rates.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
9/61. Surgical strategy for meningioma extension into the optic canal.neuroimaging of the extension of meningioma into the optic canal was evaluated for planning the surgical strategy. Intracanalicular extension and localization were retrospectively analyzed in 13 patients with frontal base meningioma near the optic canal, based on the findings of visual field defects, magnetic resonance (MR) imaging, and surgical observations. MR imaging confirmed intracanalicular localization in one of three patients with tumors extending into the optic canals, and indicated the tumor in the others. The visual field defect did not precisely correspond to the tumor localization. Unroofing of the optic canal was performed in four patients and no adverse effects were observed. The interhemispheric approach was employed for tumors localized medially in the canal, and the pterional approach for tumors localized laterally. MR imaging is useful to evaluate the intracanalicular extension, but aggressive confirmation during surgery is essential. Tailored unroofing of the optic canal and removal of the intracanalicular tumor can be performed with few adverse effects and results in good tumor control.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
10/61. Hearing restoration from deafness after resection of a large cerebellopontine angle meningioma--case report.A 61-year-old man presented with a large cerebellopontine angle meningioma manifesting as a 1-year history of deafness on the right side, in whom hearing was restored from the deaf state immediately after tumor resection. neuroimaging demonstrated a large mass in the right cerebellopontine angle, originating at the region adjacent to the jugular foramen. audiometry showed his hearing was off-scale (> 105 dB) on the right. The tumor was successfully removed through the retrosigmoid approach, and the integrity of the 7th and 8th cranial nerves was maintained. The patient regained hearing on the day after the operation, which continued to improve until near-normal. The 8th cranial nerve function may recover dramatically after removal of non-acoustic tumors, even if preoperative hearing loss is profound. To maximize the opportunity to regain hearing, approaches which devastate cochlear function should be avoided and more meticulous manipulation during tumor removal is needed.- - - - - - - - - - ranking = 1keywords = near (Clic here for more details about this article) |
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