脑膜瘤MR信号特征在诊治中的价值

目的:探讨脑膜瘤的MRI表现与病理学类型、瘤体质地之间的关系。方法:收集术前行MRI检查并经手术病理证实的63例脑膜瘤患者,将其MR信号特征与病理学类型及其瘤体质地的关系进行对照研究分析。结果:5例血管瘤脑膜瘤表现最典型,在T1WI上呈低或稍低信号,在T2WI上呈高信号,质地软。上皮型、纤维型、过渡型二种脑膜瘤在T2WI上有一定的特征性,22例纤维型脑膜瘤17例(77.3%)呈现为低及稍低信号,质地硬,17例上皮型脑膜瘤11例(64.7%)呈现为等信号,质地较硬,过渡型脑膜瘤介于其两者之间。结论:脑膜瘤的T2WI信号特征可在一定程度上反应脑膜瘤病理学类型及瘤体的质地,对指导神经外科医生的制定治疗万案具有重要的参考价值。     

Effects of therapy with [177Lu-DOTA0, Tyr3]octreotate in patients with paraganglioma, meningioma, small cell lung carcinoma, and melanoma.

Therapy using the radiolabeled somatostatin analog [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate) (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N',N'-tetraacetic acid) has been used primarily in gastroenteropancreatic neuroendocrine tumors. Here we present the effects of this therapy in a small number of patients with metastasized or inoperable paragangliomas, meningiomas, small cell lung carcinomas (SCLCs), and melanomas. METHODS: Twelve patients with paraganglioma, 5 with meningioma, 3 with SCLC, and 2 with eye melanoma were treated. Three meningiomas were very large and exophytic and all standard treatments had failed. Patients with melanoma had rapidly progressive disease (PD). The intended cumulative dose of 177Lu-octreotate was 22.2-29.6 GBq. Effects of the treatment on tumor size were evaluated using the Southwest Oncology Group criteria. RESULTS: Two of 4 patients with progressive paraganglioma had tumor regression and 1 had stable disease (SD). Of 5 patients with stable paraganglioma, 2 had SD, 2 had PD, and in 1 patient treatment outcome could not be determined. Paraganglioma was stable in 3 patients in whom the disease status at the beginning of therapy was unknown. One of 4 patients with progressive meningioma had SD and 3 patients had PD. One patient with stable meningioma at the beginning of therapy had SD. All patients with SCLC or melanoma died within 5 mo after starting therapy because of tumor progression. Although not statistically significant, a positive trend was found between high uptake on pretherapy somatostatin receptor scintigraphy and treatment outcome. CONCLUSION: 177Lu-octreotate can be effective in patients with paraganglioma and meningioma. Response rates are lower than those in patients with gastroenteropancreatic neuroendocrine tumors. Most meningiomas were very large. Further studies are needed to confirm the treatment outcome because of the limited number of patients. 177Lu-octreotate did not have antitumor effects in patients with small lung carcinoma and melanoma.     

Imaging and clinical characteristics of temporal bone meningioma

BACKGROUND AND PURPOSE: Imaging characteristics of temporal bone meningioma have not been previously reported in the literature. CT and MR imaging findings in 13 cases of temporal bone meningioma are reviewed to define specific imaging features. METHODS: A retrospective review of our institutional case archive revealed 13 cases of histologically confirmed temporal bone meningioma. CT and MR imaging studies were reviewed to characterize mass location, vector of spread, bone changes, enhancement characteristics, and intracranial patterns of involvement. Clinical presenting signs and symptoms were correlated with imaging findings. RESULTS: Thirteen temporal bone meningiomas were reviewed in 8 women and 5 men, aged 18-65 years. Meningiomas were stratified into 3 groups on the basis of location and tumor vector of spread. There were 6 tegmen tympani, 5 jugular foramen (JF), and 2 internal auditory canal (IAC) meningiomas. Tegmen tympani and JF meningiomas were characterized by spread to the middle ear cavity. IAC meningiomas, by contrast, spread to the cochlea and vestibule. Hearing loss was the most common clinical presenting feature in all cases of temporal bone meningioma (10/13). The presence of tumor adjacent to the ossicles strongly correlated with conductive hearing loss (7/9). CONCLUSION: Meningioma involving the temporal bone is rare. Three subgroups of meningioma exist in this location: tegmen tympani, JF, and IAC meningioma. Tegmen tympani and JF meningiomas spread to the middle ear cavity. IAC meningiomas spread to intralabyrinthine structures. Conductive hearing loss is commonly seen in these patients and can be surgically correctable.     

Clinicopathologic Features of Aggressive Meningioma Emphasizing the Role of Radiotherapy in Treatment

BACKGROUND AND PURPOSE: Although meningiomas are typically benign, they occasionally behave in an aggressive fashion and carry a less favorable prognosis. The aim of this study was to review the clinical, radiologic and histopathologic features of these aggressive variants as well as the outcome after multimodality therapy. PATIENTS AND METHODS: 16 patients with atypical meningiomas (n = 11) and anaplastic meningiomas (n = 5) were treated in the Departments of Neurosurgery and Radiation Oncology at the University Hospital of Philipps University Marburg, Germany, between 1997 and 2003. Tumor grading was based on new WHO criteria. There were eleven men and five women with a mean age of 54 years. The median follow-up period was 34 months. RESULTS: A total of 24 surgical procedures were performed for these 16 patients. Only seven patients underwent postoperative fractionated stereotactic radiotherapy. Patients with atypical meningioma received radiotherapy only for the recurrent disease. Six patients (37.5%) experienced tumor recurrence after a mean period of 27.2 months in spite of gross total resection. Radiographic findings suggestive of aggressiveness were observed mostly with WHO grade III meningiomas. By comparing the proliferation rate in four cases with atypical meningioma operated twice, the recurrent tumor had a higher proliferation rate than the first tumor in three cases. A special proliferation pattern was noticed in MIB-1 with anaplastic meningiomas. The mean overall survival period was 66.5 months. There was no mortality among patients with atypical meningioma, while four out of five patients with anaplastic meningioma died during follow-up. CONCLUSION: Considering the higher rate of recurrence in aggressive meningiomas even after radical surgical excision and the possibility that the recurrent tumor is more aggressive than the original one, surgery should be combined with postoperative fractionated radiotherapy to improve local tumor control. The peculiar focal expression patterns of anaplastic meningioma in MIB-1 might be a marker of such malignant development.     

Meningiomas with brain edema: radiological characteristics on MRI and review of the literature

OBJECT: Despite their benign characteristics, meningiomas are often accompanied by perifocal brain edema. The aims of this study are to determine what kind of characteristics on magnetic resonance (MR) image are indicative of a meningioma that produces brain edema and to investigate the mechanism responsible for brain edema accompanying meningiomas. METHODS: Fifty-one patients with meningioma were examined by magnetic resonance imaging (MRI), and tumor size, tumor location, shape of tumor margin, peritumoral rim, and signal intensity of tumor on T2-weighted image (T2WI) were compared and correlated with the presence versus absence of brain edema. Surgical histopathology was also examined and correlated with the MRI findings and brain edema. RESULTS: Shape of tumor margin, peritumoral rim, and signal intensity of tumor on T2WI correlated with brain edema on multivariate analyses. CONCLUSION: Invasive pattern of brain-tumor interface and hyperintensity on T2WI were indicative factors of meningiomas producing brain edema.     

The hypodense meningioma: Report of two cases

Summary Cystic or necrotic hypodense areas are occasionally seen within meningiomas on CT scans. Two diffusely hypodense endotheliomatous meningiomas are reported. The low density was due to a microcystic structure, which caused a spongy appearance and consistency.     

Primary meningeal tumors in children: correlation of clinical and CT findings with histologic type and prognosis.

PURPOSE: To identify the radiologic features that might help in preoperative differentiation of the meningiomas from the remaining primary meningeal tumors, in particular the malignant tumors. METHODS: The clinical and computed tomographic features of 21 children with histologically proved primary meningeal tumors were analyzed. FINDINGS: Benign tumors (meningiomas) are more likely to occur in older children, to have longer symptom duration, and to have CT appearances similar to the "typical" adult meningioma. Atypical CT features suggest a malignant meningeal tumor, such as meningeal sarcoma, melanoma, or meningeal primitive neuroectodermal tumor. The recent identification of a new subtype of meningioma (a "sclerosing" group) is discussed. This is common in children and the CT and clinical features are similar to those seen in other meningiomas. It is frequently mistaken histologically for an intraaxial tumor, or for an atypical or malignant meningioma. These sclerosing meningiomas may also show brain invasion but despite this, in the short term, the prognosis is no different from other meningiomas. CONCLUSION: The bad reputation previously ascribed to childhood primary meningeal tumors should be confined to that small group that are malignant. Meningiomas have a more favorable outlook.     

囊性脑膜瘤的MRI表现(附37例报告)

目的探讨囊性脑膜瘤的MR I表现,以提高诊断准确率。方法囊性脑膜瘤患者37例,采用1.5T磁共振扫描仪分别行轴位、矢状位和冠状位颅脑扫描,其中20例行Gd-DTPA增强扫描。观察囊性脑膜瘤的MR I表现,并分析不同类型囊性脑膜瘤的特点。结果囊性脑膜瘤除具有脑膜瘤常见的MR I表现外,由于囊腔的存在,囊性脑膜瘤的信号不均匀,周围常有明显脑水肿,肿瘤边缘模糊不清较脑膜瘤多见。3例Nauta 1型囊性脑膜瘤中,囊变、坏死位于肿瘤中央,16例Nauta 2型囊性脑膜瘤中,囊变、坏死位于肿瘤周边,Nauta 1型和Nauta 2型囊性脑膜瘤的囊腔四周均有肿瘤组织。3例Nauta 3型和5例Nauta 4型囊性脑膜瘤中,坏死、囊变区位于肿瘤实质部分的周边,Nauta 3型者肿瘤和囊腔之间有脑组织相隔,而Nauta 4型中肿瘤则与囊腔直接相邻。10例为上述4型中某2种或2种以上的混合型。结论MR I对囊性脑膜瘤的诊断和分型有较大价值。     

脑膜瘤的MRI征象及相关病理(附51例病例分析)

目的:分析脑膜瘤MRI表现及其相关病理.方法:回顾性分析51例经手术证实的脑膜瘤MRI图像,从其信号特点、肿瘤-脑组织界面、瘤周水肿、脑膜尾征病灶增强后MRI信号均匀度等方面进行归纳,并观察相关病理学资料.结果:脑膜瘤大多T1WI为等低信号,T2WI以稍高信号和混杂信号多见,脑膜尾征具有诊断价值.结论:脑膜瘤MRI征象有较高的敏感性和特征性,大多数能在术前诊断,为手术方式提供帮助.     

Glucose utilization by intracranial meningiomas as an index of tumor aggressivity and probability of recurrence: a PET study

Seventeen patients with intracranial meningiomas were studied with positron emission tomography and fluorine-18-2-fluorodeoxyglucose (PET-FDG) to assess the glucose utilization of these tumors. Four meningiomas followed for 3-5 years after PET-FDG and surgery showed no evidence of recurrence. These tumors had significantly lower glucose utilization rates (1.9 mg/dl/min +/- 1.0) than 11 recurrent or regrowing meningiomas (4.5 mg/dl/min +/- 1.96) (P less than .01). The glucose metabolic rates of meningiomas correlated with tumor growth, as estimated from changes in tumor size on repeated computed tomographic scans. Histopathologically, a syncytial (atypical) meningioma had the highest glucose utilization rate, followed by a papillary meningioma and an angioblastic meningioma. Individual transitional and syncytial (typical) meningiomas showed marked differences in glucose metabolism despite similar microscopic appearance. Glucose utilization rate appears to be at least as reliable as histologic classification and other proposed criteria for predicting the behavior and recurrence of intracranial meningiomas.     

Multiple pulmonary metastases from intracranial meningioma: MR imaging findings (case report)

Extracranial metastases from meningioma are very rare and among those the lungs are the most common metastatic site. In the literature, pulmonary metastases of meningiomas have been emphasized on their rarity, non-specific imaging findings, and cytologic features. Some definitive MR imaging features of intracranial meningiomas have been described. However, MR imaging findings of the lung metastases of meningiomas have not been investigated with regard to these diagnostic imaging features. In this report, similarities between MR imaging features of primary intracranial meningioma and its rare lung metastases are presented.     

脑膜瘤

根据WHO的中枢神经系统肿瘤分类，脑膜瘤分为四类：①脑膜瘤。②脑膜间质非脑膜上皮肿瘤。③原发性黑素细胞病变。④组织来源不明的血管母细胞瘤。脑膜瘤是一组分为15个亚型和3个恶性级别的杂类肿瘤，在脑膜肿瘤中最为多见。本文复习它们的影像学，介绍侵袭性脑膜瘤的概念和影像学表现。已经肯定，大多数骨质增生是由肿瘤直接浸润所致，对此情况应考虑侵袭性脑膜瘤的诊断。单个脑膜瘤可能为硬脑膜上范围相对较大的肿瘤野中生长突出而能见到。基于这个概念，复发性脑膜瘤可分为两类：真性或局部性复发；假性或区域性的复发。非典型性和间变性脑膜瘤的影像学诊断是一个尚未解决的问题。本文对它们的CT和MRI的恶性征象及其可靠性进行探讨，本文叙述了囊性脑膜瘤和无症状性脑膜瘤的影像学，并对MRI所见脑膜尾征的意义进行探讨。     

脑膜瘤伴瘤周水肿的MRI特征分析

目的:探讨脑膜瘤伴瘤周水肿的机制。方法:49例经手术病理证实的脑膜瘤,回顾性分析伴有瘤周水肿脑膜瘤的MRI特征,用Fisher′s检验比较肿瘤大小、部位、边缘、假包膜征及肿瘤T2WI信号与瘤周水肿发生的关系。结果:肿瘤边缘、假包膜征和肿瘤T2WI信号与脑膜瘤瘤周水肿发生明显相关,P值分别是0.016,0.004 和0.041。结论:脑膜瘤脑界面侵袭性模式和T2WI高信号是提示脑膜瘤发生瘤周水肿的因素。     

Fractionated Stereotactic Radiation Therapy in the Management of Benign Cavernous Sinus Meningiomas

PURPOSE: To analyze own long-term results with fractionated stereotactic radiotherapy (FSRT) in patients with benign meningiomas of the cavernous sinus and to review the literature on these rare lesions. PATIENTS AND METHODS: 57 patients were treated with FSRT for benign meningiomas of the cavernous sinus between 01/1990 and 12/2003 at the authors' institution. Histology was WHO grade I in 28/57 lesions, and undetermined in 29/57 lesions. 29 patients received radiotherapy as primary treatment, ten following surgery, and 18 patients were irradiated for recurrent disease. Median target volume was 35.2 cm3. Median total dose was 57.6 Gy with 1.8 Gy per fraction. 51/57 patients showed clinical symptoms before radiotherapy like reduced vision (n = 19), diplopia (n = 25), or trigeminal hyp-/dysesthesia (n = 17). RESULTS: Median follow-up period was 6.5 years. 50/57 patients were followed for > 36 months. Overall local tumor control was 100%. 39/57 patients had stable disease based on CT/MRI, while 18/57 had a partial remission of tumor volume. Overall survival for patients with WHO grade I meningiomas was 95.5% after 5 and 10 years. Two patients died 2.8 and 4.1 years after radiotherapy due to cardiac failure. In 11/57 patients, preexisting neurologic deficits improved. There was one patient with recurrent hyperlacrimation of one eye on the side of the irradiated meningioma. Three patients complained about subjective visual deterioration after FSRT without any objective findings in an ophthalmologic examination. No late toxicity RTOG >/= degrees III was seen. CONCLUSION: These data demonstrate that FSRT is an effective and safe treatment modality for local control of benign cavernous sinus meningiomas with a minimal risk of significant late toxicity.     

Contribution of dynamic contrast MR imaging to the differentiation between dural metastasis and meningioma

Purpose To determine the perfusion-sensitive characteristics of cerebral dural metastases and compare them with the data on meningiomas.Methods Twenty-two patients presenting with dural tumor underwent conventional and dynamic susceptibility-contrast MR imaging: breast carcinoma metastases, two patients; colorectal carcinoma metastasis, one patient; lung carcinoma metastasis, one patient; Merkel carcinoma metastasis, one patient; lymphoma, one patient; meningiomas, 16 patients. The imaging characteristics were analyzed using conventional MR imaging. The cerebral blood volume (CBV) maps were obtained for each patient and the relative CBV (rCBV) in different areas was calculated using the ratio between the CBV in the pathological area (CBVp) and in the contralateral white matter (CBVn).Results The differentiation between a meningioma and a dural metastasis can be difficult using conventional MR imaging. The rCBVs of lung carcinoma metastasis (1 case: 1.26), lymphoma (1 case: 1.29), breast carcinoma metastasis (2 cases: 1.50,1.56) and rectal carcinoma metastasis (1 case: 3.34) were significantly lower than that of meningiomas (16 cases: mean rCBV = 8.97±4.34, range 4–18). Merkel carcinoma metastasis (1 case: 7.56) showed an elevated rCBV, not different from that of meningiomas.Conclusion Dural metastases are sometimes indistinguishable from meningiomas using conventional MR imaging. rCBV mapping can provide additional information by demonstrating a low rCBV which may suggest the diagnosis of metastasis.     

恶性脑膜瘤的MRI表现分析

目的：探讨恶性脑膜瘤的MRI表现,提高其诊断准确率。方法：回顾分析67例经手术病理证实的恶性脑膜瘤临床、病理及MRI资料。结果：肿瘤形态多呈分叶状（26/67）、蘑菇状（7/67）及不规则状（29/67）;肿瘤边缘模糊或部分边缘与周围脑组织、邻近组织分界不清：表现为单纯蛛网膜受侵犯26例、硬脑膜受侵犯18例、脑组织受侵犯8例、脑外组织受侵犯4例;肿瘤信号改变：T1WI呈等、低信号60例、等、高信号3例及较均匀信号4例,T2WI呈不均匀信号64例、较均匀信号3例,增强后均显示不均匀强化;肿瘤恶性度与瘤周水肿具有一定的关联性,瘤周水肿形态表现为：圆晕状水肿20例、指压状水肿18例、不规则水肿24例。结论：恶性脑膜瘤的MRI表现具有一定特征性,但需要注意与良性脑膜瘤鉴别。     

"Benign" metastasizing meningiomas

Less than one in 1000 meningiomas metastasizes. Although the angioblastic and hemangiopericytic tumors are believed by some authors to metastasize with a greater frequency than the other histologic forms of meningioma, most investigators believe that neither the histologic pattern, local aggressiveness, size, nor location of the tumor can be used accurately to predict which tumors will metastasize. Three new cases are presented, bringing the total reported number of metastasizing meningiomas to 113. If the angioblastic meningiomas and hemangiopericytomas are eliminated from this group, 69 reported cases of "benign" metastasizing meningioma remain.     

Hemorrhagic complications in embolization of a meningioma: Case report and review of the literature

We report a case of hemorrhage in a parasellar meningioma shortly after embolization of the dural cavernous carotid artery branches supplying the tumor. This represents the first report of hemorrhage within a meningioma resulting from embolization with small (50- to 150-μm) polyvinyl alcohol particles, as well as the first reported case of hemorrhage complicating meningioma embolization from internal rather than external carotid artery branch embolization. We also review previously reported cases of postembolization hemorrhage from meningiomas. Received: 16 August 1996 Accepted: 4 April 1997     

Dural invasion of meningiomas adjacent to the tumor margin on Gd-DTPA-enhanced MR images: histopathologic correlation

In intracranial meningiomas a flat, contrast-enhancing, dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA-enhanced MR images. We wished to evaluate whether there is a correlation between MR images and meningeal invasion of intracranial meningiomas. The study included 54 patients with intracranial meningioma and the meningeal sign. MR studies included T2-weighted and gadolinium-DTPA-enhanced T1-weighted images in axial, coronal, and sagittal planes. Histopathologic examinations were done on the meningiomas adjacent to the dura mater. The meningeal sign on MRI was observed from 2 up to 35 mm from the main tumor mass in 31 (57 %) of the 54 patients. In 20 of these 31 the histopathologic examination showed tumor invasion, while 11 patients had no tumor invasion but tissue proliferation, hypervascularity, and vascular dilatation. Seven of the 23 meningiomas without the meningeal sign had histologically proven infiltration of the adjacent dura. MR imaging is not able to determine definitive whether or not there is dural infiltration of the meningiomas. In conclusion, resection of the tumor with a wide margin is necessary to achieve complete excision of meningioma and to avoid recurrence. Received 23 July 1997; Revision received 10 October 1997; Accepted 17 October 1997     

少见型脑膜瘤的CT诊断

目的探讨颅内少见型脑膜瘤的CT表现,并提高其诊断准确性。方法15例经手术病理证实的少见型脑膜瘤,包括Nauta型囊性脑膜瘤8例,恶性脑膜瘤4例,多发性脑膜瘤2例以及完全钙化性脑膜瘤1例,术前均经CT平扫,14例又经对比增强扫描。对所有患者的CT表现结合文献复习进行了回顾性分析。结果多数脑膜瘤位于幕上。Nauta型囊性脑膜瘤CT平扫呈囊实性肿块,增强扫描示肿瘤实质部分明显强化,部分囊壁有强化。恶性脑膜瘤CT平扫呈不规则形混杂密度肿块,或囊性肿块伴结节,肿瘤边缘不规则,增强后实质部分明显强化,瘤周水肿广泛。多发性脑膜瘤CT平扫示多发结节灶,增强扫描示肿瘤轻度强化。完全钙化性脑膜瘤CT平扫呈钙化团块,邻近颅骨骨质增生硬化,瘤周无水肿。本组CT术前正确诊断10例,误诊5例。结论颅内少见型脑膜瘤术前CT易误诊。综合分析各型的CT特征,有助于作出正确诊断和鉴别诊断。