1/96. Biomodel-guided stereotaxy.OBJECTIVES: To simplify the practice of stereotactic surgery by using an original method, apparatus, and solid anatomic replica for trajectory planning and to validate the method and apparatus in a laboratory and clinical trial. methods: The patient is marked with fiducials and scanned by using computed tomography or magnetic resonance imaging. The three-dimensional data are converted to a format acceptable to stereolithography. Stereolithography uses a laser to polymerize photosensitive resin into a solid plastic model (biomodel). Stereolithography can replicate blood vessels, soft tissue, tumor, and bone accurately (<0.8 mm). A stereotactic apparatus is referenced to fiducials replicated in the biomodel. The trajectory for the intervention is determined and saved. The apparatus is attached to the patient fiducials, and the intervention is replicated. RESULTS: Three types of apparatus (template, Brown-Roberts-Wells frame, and D'Urso frame) were tested on phantoms and patients requiring the excision/biopsy of tumors. The localization errors determined from the phantom studies were template, 0.82 mm; Brown-Roberts-Wells frame, 1.17 mm; and D'Urso frame, 0.89 mm. The surgeons reported that clinical use of the template and D'Urso frame was accurate and ergonomic. The Brown-Roberts-Wells frame was more difficult to use and somewhat inaccurate. CONCLUSION: Biomodel-guided stereotaxy has significant advantages. It is performed quickly; it is based on simple, intuitive methodology; it enhances visualization of anatomy and trajectory planning; it enhances patient understanding; it uses inexpensive equipment; it does not require rigid head fixation; and it has greater versatility than known techniques. Disadvantages are biomodel cost and a manufacturing time of 12 to 24 hours.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
2/96. A new subtype of meningioma.Three patients with small meningiomas presented with diffuse cerebral edema that was out of proportion to the size of tumors. All lesions were small and no brain invasion or unusual tumor vascularity or dural sinus involvement was noted in any of the three cases. Tumor material was subjected to conventional and immunohistochemical stains. All three tumors showed benign meningothelial components, prominent formation of hyaline inclusions (pseudopsammoma bodies), and striking vascular mural proliferation of small dark cells. All patients have remained asymptomatic without any evidence of tumor recurrence after a follow-up of 4-6 years. These tumors showed proliferation of pericytes in blood vessel walls and, therefore, represent a new subtype of meningothelial meningioma. In the study presented here, the location, size, histotype, and clinical findings that may influence the development of peritumoral brain edema are discussed in detail.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
3/96. Presumed intraventricular meningioma treated by embolisation and the gamma knife.A 58-year-old woman with a presumed incidentally discovered meningioma in the left lateral ventricle was treated by superselective embolisation and gamma knife therapy. The diameter of the tumour was 40 mm, and its main feeding artery was the left lateral posterior choroidal artery. This vessel was embolised with microcoils. At 8 months following embolisation, the diameter of the tumour had decreased and was stable. The gamma knife was chosen as an adjuvant therapy for the further control 13 months after embolisation. Embolisation and gamma knife therapy may be an alternative treatment for meningiomas where surgical resection appears difficult.- - - - - - - - - - ranking = 0.18191711478813keywords = vessel (Clic here for more details about this article) |
4/96. Falx meningioma presenting as acute subdural hematoma: case report.BACKGROUND: Acute subdural hematomas caused by meningiomas have been rarely encountered. Pathophysiologic mechanisms and clinical considerations in these patients have not been sufficiently explored. We addressed the possible mechanism of spontaneous hemorrhage in our case and briefly discuss the optimal treatment. CASE DESCRIPTION: This case of falx meningioma presenting as an acute subdural hematoma in a 78-year-old woman is described. On initial computed tomography (CT), an enhancing tumor of the falx appeared to be the cause of hemorrhage. Only faint contrast staining in the periphery of the tumor was seen on right external carotid arteriograms, with no evidence of other vascular supply. Extravasation of contrast material during the procedure occurred suddenly and was successfully treated by endovascular embolization using a microcatheter. The hematoma was emergently evacuated with gross total removal of the tumor. Pathologic examination confirmed a transitional meningioma with abundant hyalinized structures. Disruption of a thin-walled vessel adjacent to the tumor capsule was assumed to be the site of hemorrhage. CONCLUSIONS: The longstanding ischemia of the tumor was considered to have produced the deposition of hyalin in the tissue, which changed the hemodynamics within the tumor, producing vascular stress leading to rupture. The prognosis of patients with meningiomas complicated by acute subdural hematoma is generally poor, with mortality reported in approximately one-half of such patients. Surgical exploration is the most effective treatment and should be conducted before irreversible brain damage has occurred.- - - - - - - - - - ranking = 0.18191711478813keywords = vessel (Clic here for more details about this article) |
5/96. Secretory meningioma of the brain. Report of two cases.Two cases of cerebral secretory meningioma, occurring in 57 and 33-year-old females are reported. The tumors were located in the tentorial and frontotemporal region, respectively. The general histologic appearance of the tumors was of meningothelial meningioma (case 1) and meningioma with microcystic and angiomatous features (case 2). The most striking histological finding in both tumors were numerous pseudopsammoma bodies, localized chiefly around blood vessels. The inclusions were slightly eosinophilic, stained strongly with PAS method and were differing in size from 3 to 30 microns. Tumor cells containing or surrounding pseudopsammomas were immunopositive for cytokeratin and epithelial membrane antigen. In the first case, individual pseudopsammomas were strongly positive for carcinoembryonic antigen. Some diagnostic aspects of this antigen and problems regarding differential diagnosis in secretory meningioma are briefly discussed.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
6/96. Off-pump CABG for a patient with a brain tumor.coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG) was performed on a patient with a brain tumor. A patient with effort angina of the left anterior descending artery (LAD), and diagonal branch stenosis was referred to us for CABG. He had a mass lesion in the brain that was diagnosed as meningioma involving the internal carotid artery and a middle cerebral artery. To avoid brain complications, we performed off-pump CABG using the internal thoracic and radial arteries to the LAD and a diagonal branch. Off-pump CABG was an effective method to avoid brain complications for patients with a brain tumor involving cerebral vessels.- - - - - - - - - - ranking = 0.18191711478813keywords = vessel (Clic here for more details about this article) |
7/96. Solitary fibrous tumor arising from the falx cerebri--case report.A 50-year-old female was admitted with headache and visual disturbance. neuroimaging demonstrated a well-demarcated large tumor attached to the falx cerebri. The tumor was totally removed by surgery. Histological examination showed that the tumor consisted of spindle cells with no pattern in the collagenous background. Staghorn-like blood vessels were common. Immunohistochemical study showed the tumor cells were strongly positive for CD34 and vimentin, but negative for epithelial membrane antigen. The diagnosis was solitary fibrous tumor arising from the falx cerebri. Solitary fibrous tumor is rare within the cranial cavity, and can be distinguished from meningioma and hemangiopericytoma by the histological, ultrastructural, and immunohistochemical findings.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
8/96. Ultrastructural examination is essential for diagnosis of papillary meningioma.AIMS: Papillary meningioma is a rare meningeal tumour. To date only a few cases have been reported and their immunohistochemical features have not been fully documented. methods AND RESULTS: A 49-year-old woman presented with a 2-month history of headaches and memory disturbance. CT and MRI imaging showed an enhancing pineal mass with extension into the occipital lobes and invasion of the splenium. At surgery, the tumour was found to be tough and vascular with a well-defined capsule. No recurrence was noted 19 months after the operation. In another case a 44-year-old woman was admitted with 1-month history of headaches, poor memory, imbalance and diplopia. CT scan showed a large hyperdense, uniformly, enhancing mass within the middle cranial fossa at the petrous ridge. The tumour recurred 19 and 25 months after first resection. The histology of both tumours was similar. The neoplasms contained polygonal cells with a moderate amount of cytoplasm, rounded regular nuclei and distinct cell borders. The cells were arranged radially around the blood vessels (perivascular pattern) and a papillary pattern was seen only focally. Mitotic figures were moderately frequent. immunohistochemistry showed that both tumours were immunoreactive to vimentin and NSE, whereas GFAP, CAM5.2, EMA, S100 protein and synaptophysin were negative. Electron microscopy revealed interdigitating cell processes, desmosomes and intermediate filaments. CONCLUSIONS: The histological and immunohistochemical features of these two tumours are complex and difficult to interpret. Although papillary meningiomas were considered in our initial differential diagnosis, the final conclusion was possible only when the ultrastructural features were revealed.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
9/96. Dural congestion accompanying meningioma invasion into vessels: the dural tail sign.Our purpose was to verify the histological appearance of the dural tail accompanying meningiomas on MRI. We studied seven patients such a dural tale. We examined the point of attachment of the tumour and the adjacent dura mater histologically. In all patients, rich vascularity and dilated vessels were observed in the dura mater at the point of attachment of the tumour; tumour cells invaded the dura mater and vessels, packing the latter. In the adjacent dura mater, showing as a dural tail on MRI, there was tumour-cell invasion in only one patient. Vascular congestion around the vessels compacted by the tumour cells in the dura mater and dilated vessels were seen in all patients. We therefore suggest that the mechanism of the dural tail sign is as follows. First, tumour cells invade vessels and pack them at the point of tumour attachment. Then, vessel congestion is induced in the adjacent dura mater, as a result of which it enhances markedly, giving rise to the dural tail sign.- - - - - - - - - - ranking = 1.8191711478813keywords = vessel (Clic here for more details about this article) |
10/96. Meckel's cave meningiomas with subarachnoid hemorrhage.Two patients with Meckel's Cave meningiomas were initially hospitalized as a result of subarachnoid hemorrhage. Four-vessel angiography was necessary to exclude other causes of bleeding while demonstrating these lesions. Apoplectic presentation in both cases led to early diagnosis and successful surgical therapy. A review of the literature reveals subarachnoid hemorrhage to be a rarity in association with meningiomas. The two patients currently reported are believed to be the only examples on record of hemorrhagic meningiomas arising from the region of Meckel's Cave.- - - - - - - - - - ranking = 0.18191711478813keywords = vessel (Clic here for more details about this article) |
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