Search results for "Meningioma"
showing 10 items of 71 documents
Intrinsic Expression of Drug Resistance-Associated Factors in Meningiomas
2001
Meningiomas, commonly benign tumors, rarely display aggressive behavior by recurrences and invasion. In addition to surgery, irradiation is beneficial for recurrent, atypical, and malignant meningiomas. The role of chemotherapy, however, remains controversial, although there is evidence that meningiomas respond well to adjuvant chemotherapy. A major obstacle in chemotherapy remains drug resistance with reduced cellular drug accumulation through membrane efflux pumps, drug detoxification, and alterations in drug target specificity. In 84 classic, atypical, and malignant meningiomas, the immunohistochemical expression profile of P-glycoprotein (P-gp), multidrug resistance-associated protein (…
Microsurgical treatment of midfacial tumours involving the skull base
1998
Various approaches to the base of the skull for the treatment of cranial base tumours are described in detail. Advantages and disadvantages of the particular approaches are discussed. This clinical experience is based on 303 neoplasms involving the base of the skull, operated on by the authors. Retrospective survival studies are presented and a review of the literature on the subject is discussed. Utilizing microsurgical techniques the 2-, 3- and 5-year survival rates were significantly improved. The functional and aesthetic outcomes were also dramatically superior compared with standard ablative procedures. Reconstructive postoperative strategies are suggested.
Gene expression profiles of metabolic aggressiveness and tumor recurrence in benign meningioma.
2013
Around 20% of meningiomas histologically benign may be clinically aggressive and recur. This strongly affects management of meningioma patients. There is a need to evaluate the potential aggressiveness of an individual meningioma. Additional criteria for better classification of meningiomas will improve clinical decisions as well as patient follow up strategy after surgery. The aim of this study was to determine the relationship between gene expression profiles and new metabolic subgroups of benign meningioma with potential clinical relevance. Forty benign and fourteen atypical meningioma tissue samples were included in the study. We obtained metabolic profiles by NMR and recurrence after s…
The course of intracranial pressure and volume-pressure relationships following extirpation of meningiomas and astrocytomas
1978
Thirty-five patients with meningiomas were compared with 37 patients with astrocytomas with respect to the postoperative course of their ICP and elastance. In the case of the meningioma patients, the ICP increased on average over a longer period and achieved higher values than in the astrocytoma patients. In the first group, the elastance attained values that were three times as high as in the second group. There was no fixed relationship between pressure and elastance in the two groups of patients.
Histologically benign metastatic meningioma: morphological and cytogenetic study. Case report.
2003
✓ The authors report on a 75-year-old man with histologically benign fibroblastic meningioma metastasizing to the lung, liver, spleen, and kidney. The original tumor exhibited a complex karyotype involving different structural and numerical anomalies associated with monosomy of chromosome 22. The implication of chromosome 1p36 was confirmed by fluorescence in situ hybridization in most interphase nuclei. Metastases occurred 4 months after incomplete resection with prior therapeutic embolization. The recurrent tumor in turn displayed anaplastic features and an increased Ki-67 labeling index. Genetic alterations in such morphologically benign meningiomas have been implicated in the malignant …
Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability
2015
Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour w…
Ten-year Experience with the Supraorbital Subfrontal Approach through an Eyebrow Skin Incision
2005
Abstract OBJECTIVE: More than ever before, the priority in contemporary neurosurgery is to achieve the greatest therapeutic effect while causing the least iatrogenic injury. The evolution of microsurgical techniques with refined instrumentation and illumination and the enormous development of preoperative and intraoperative diagnostic tools enable neurosurgeons to treat different lesions through limited and specific keyhole approaches. METHODS: Based on our surgical experience, the technique of supraorbital subfrontal craniotomy is described in detail in this article. After an eyebrow skin incision is made, a limited supraorbital craniotomy is performed with a width of 15 to 25 mm and a hei…
Evaluación del índice de proliferación Ki-67 como predictor de recidiva en Meningiomas cerebrales grado I de la OMS. Comparación con la escala de res…
2016
Introducción: Los meningiomas representan el 13-26% de tumores primarios intracraneales, con una incidencia anual de 2-4 nuevos casos/100000 habitantes año, siendo su tratamiento de elección la cirugía. Cerca de un 90% de los meningiomas son categorizados como grado I histológico y su tasa de recurrencia se cifra entre un 7-20%. Según sus características histopatológicas se clasifican siguiendo los parámetros de la OMS, si bien no existen factores histológicos o moleculares que puedan predecir su recidiva de forma cierta, siendo el principal factor descrito en la literatura en este sentido el grado de exéresis de acuerdo a la escala de resección de Simpson. Hipótesis y Objetivos: El índice …
Neurosurgical Odyssey: Case of Anaplastic Meningiomatosis.
2017
According to the World Health Organization grading, meningiomas are classified as grade I (benign), grade II (atypical), and grade III (anaplastic). Most of them (81%) are benign, 15% are atypical, and 4% are anaplastic. Metastasis is a rare event in meningiomas, occurring in <1% of cases. In most types of tumors, distant metastasis is an incontrovertible indication of malignancy. This is not so clearly the case with meningiomas, mostly in the multiple localization of these tumors, known as meningiomatosis. Here we would like to share our experience with a unique case of an atypical meningioma, which evolved in an anaplastic multiple meningiomatosis, invading the brain and associated wit…
Suprasellar Granular Cell Tumor
1992
A case of a suprasellar granular cell tumor, approximately 1.5 cm in diameter, in a 68-year-old woman is described. Diagnosis was established postoperatively by histopathological examination of the tumor tissue. The preoperative computed tomographic scan revealed a slightly hyperdense suprasellar mass with strong contrast enhancement. There was no evidence of calcification. The T1-weighted image on magnetic resonance imaging scan showed an isointense tumor with non-homogeneous enhancement after intravenous gadolinium diethylene-triamine-pentaacetic acid. In the proton-weighted image, the suprasellar mass presented a non-homogeneously enhanced signal. A non-homogeneous signal reduction was s…