Investigation of blood flow in meningothelial and fibrous meningiomas by xenon-enhanced CT scanning

We investigated whether xenon-enhanced computed tomography was able to separate meningothelial meningioma from fibrous meningioma. Cerebral blood flow was studied by xenon-enhanced computed tomography in six patients with incidentally detected intracranial meningiomas. All of the tumors were small (< 32 mm) and there was little or no peritumoral edema. Three patients had meningothelial meningioma and three patients had fibrous meningioma. The tumor blood flow and the contralateral tissue blood flow were determined. The ratio of these parameters was 1.753 +/- 0.467 for meningothelial meningiomas and 0.809 +/- 0.105 for fibrous meningiomas, with a significant difference between the two tumor subtypes (p = 0.0185). There was no correlation between the signal intensity on magnetic resonance imaging and tumor subtype, and the findings on cerebral angiography also did not indicate the subtype. In conclusion, xenon-enhanced computed tomography showed a difference between smaller meningothelial and fibrous meningiomas in patients with normal surrounding brain tissue. We could not confirm that xenon-enhanced computed tomography was able to distinguish the subtype of meningioma because of the small number of subjects in this study, but our findings might expand interest in the clinical use of this method.     

Cytoplasmic iron deposition is associated with the expression of oxidative DNA damage marker in meningiomas

Angiomatous meningiomas are rare meningioma subtypes, which are characterized by abundant, well‐formed vessels. We encountered two cases of newly diagnosed angiomatous meningiomas exhibiting tumor cells with brown pigments, which were histochemically proven to be iron. In an attempt to understand its pathological significance, we assessed this unusual finding in representatives for each grade of meningiomas and immunoexpression of transferrin receptor (CD71) and the oxidative DNA damage marker, 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG). Iron deposition in the tumor cells was observed in 8/15 (53%) angiomatous meningioma cases, 2/6 (33%) microcystic meningiomas and 2/20 (10%) meningothelial meningiomas, which included clustered microvessels, but not in fibrous, atypical or anaplastic meningiomas (P = 0.001). Cytoplasmic CD71 expression was largely negative in angiomatous meningioma cases, but positive in meningothelial and high‐grade meningiomas, suggesting that the transferrin‐dependent iron transporter was involved in iron uptake in meningiomas. Nuclear expression of 8‐OHdG was observed in ≥50% of the tumor cells in all 15 cases of angiomatous meningioma and was associated with the presence of regressive histopathological findings, such as hyalinized vessels and cystic changes. In addition, the fraction of iron‐containing tumor cells was correlated to those expressing 8‐OHdG (P = 0.005). Our finding indicates that cytoplasmic iron deposition in tumor cells is characteristic of highly vascularized benign meningiomas and related to increased oxidative DNA damage markers.     

Sclerosing meningioma: immunohistochemical analysis of five cases

Sclerosing meningioma is a rare morphologic subtype of meningioma and may be mistaken for atypical or malignant meningioma and astrocytoma or schwannoma because of marked collagen deposits and a sparse population of cells with little resemblance to meningothelial cells. Authors describe the histopathologic and immunophenotypic features of five cases of sclerosing meningioma. Histologically, all the cases consisted of paucicellular collagenous tissue containing spindle cells with or without small foci of meningothelial cell proliferation. The morphology and immunohistochemical profile of the spindle cells were different from those of conventional meningothelial cells. The meningothelial cells showed a typical immunoreactivity of conventional meningiomas, while the spindle cells displayed a strong expression of vimentin. The Ki-67 labelling index was uniformly low in all cases, and none of cases expressed p53 protein. In summary, the recognition of meningothelial cells in massively sclerotic lesions is helpful for a correct diagnosis. In the cases with a total absence of meningothelial cells, however, the vague collagenous whorls are more diagnostic rather than immunohistochemistry. Considering association with clear cell meningioma, prospective and retrospective long-term follow-up is necessary for deciding whether reminiscent clear cell meningiomas should be separated from sclerosing meningioma or not.     

Intracranial cystic meningiomas: A series of six patients

ObjectiveAlthough meningiomas are the most common primary non-glial intracranial tumors, cystic meningiomas are quite rare. This study presents six cases in order to discuss the radiological and pathological features of cystic meningiomas.Patients and methodsSix patients with cystic meningiomas were included in the study. All patients underwent a cranial computed tomography scan and magnetic resonance imaging (MRI) evaluation, pre- and postoperatively.ResultsAll patients presented with long standing headache dating back at least two years. There was no gender predominance in our series. Radiological evaluation revealed two parasagittal and two convexity meningiomas located at the frontal region. Two lesions were located at the tuberculum sellae and the foramen magnum. All of the tumors were totally excised (Simpson Grade I or II). Pathology results included meningothelial meningioma in three patients, angiomatous meningioma in two patients, and metaplastic meningioma in one patient. In two patients, the cystic meningiomas were resected with the use of sodium fluorescein (Na-Fl) under a YELLOW 560 nm microscope filter. Na-Fl was found to be very useful in demonstrating the brain–tumor interface, and it was especially effective in resecting the cyst wall of the peritumoural cystic meningiomas. None of the patients had any complications, and no recurrences were noted in any of the patients within the mean follow-up period of 51 months (range: 16–102 months).ConclusionIt is important to note MRI changes specific to cystic meningioma and include meningiomas in the differential diagnosis of intracranial cystic lesions. The use of sodium fluorescein (Na-Fl) under a YELLOW 560 nm microscope filter is a useful tool to differentiate the brain-tumor interface, as well as to identify the cyst wall in order to fully resect the tumor with the cystic component to avoid recurrence and achieve better clinical results.     

Assessment of hemodynamics of meningioma with dynamic MR imaging]

Dynamic MR imaging provides hemodynamic information about normal and pathologic tissue of the brain. The purpose of our study was to evaluate the usefulness of dynamic MR imaging in the assessment of tumor vascularity and the tumor tissue blood flow of meningiomas. We studied 13 patients with meningiomas using dynamic spin-echo MR imaging. The histological subtypes of meningioma were confirmed by the examination of surgical specimens in all patients, and tumors were meningothelial in 9 cases, fibrous in 2, transitional in 1, and psammomatous in 1. Serial images were obtained every 18-24 sec for 8 minutes and 30 seconds after rapid injection of gadolinium diethylenetriaminepentaacetic acid. Different parameters (time to peak, maximum of signal intensity and the washout ratio) were calculated directly from signal intensity curves. As an indicator of tumor vascularity, microvessel density was counted based on immunohistochemically stained sections and tumor tissue blood flow was measured using an xenon-CT system. The maximum of signal intensity corresponded to the tumor vascularity. With dynamic MR imaging, the time intensity curves (TI curves) were divided into two patterns; type 1 had a steep increase with a peak and type 2 had a slow increase to a peak followed by plateau. The maximum of signal intensity measured from TI curve of dynamic MR imaging correlated significantly with microvessel density (R2 = 0.840, p < 0.0001). Linear regression revealed a significant positive relation between the washout ratio and the tumor tissue blood flow in group showed type 1 on TI curve (R2 = 0.961, p < 0.001). There was also a significant negative correlation between the time to peak and the tumor tissue blood flow (R2 = 0.792, p < 0.01). We suggest that dynamic MR imaging is useful for evaluating hemodynamics of meningiomas.     

Extracranially extended meningothelial meningiomas with a high MIB‐1 index: A report of two cases

Meningiomas that extend from the meninges to the extracranial tissue and result in skull osteolysis have been known to take an aggressive clinical course. Two such cases in elderly patients are reported. Case 1 is an 82‐year‐old woman who had undergone removal of the parasagittal meningioma (meningothelial meningioma with 5% of MIB‐1 index) 4 years and 6 months previously, developed recurrence of the tumor that extended to extracranial soft tissue. Biopsy obtained from the subcutaneous tissue showed an atypical meningothelial meningioma with 20% of MIB‐1 index. In case 2 an 84‐year‐old man, who developed rapidly progressing dementia and gait disturbance, the MRI study revealed an intracranial‐extraaxial right frontal tumor with an extracranial extension resulting in skull osteolysis. Pathological examination of the totally resected tumor identified meningothelial meningioma, but MIB‐1 index of the intracranial portion of the tumor was less than 0.1%, while that of the extracranial portion was approximately 15%. Although the meningiomas presently reported failed to show histological features of malignancy, the high MIB‐1 index indicated that they were rapidly growing tumors. In the present report it is considered that meningioma cells that invade the skull and extracranial tissue are biologically aggressive and require total resection, as long as the condition of the patients is feasible for surgery.     

Falx Meningiomas: Surgical Results and Lessons Learned from 68 Cases

Objective

The purpose of this study was to review the characteristics of falcine meningioma retrospectively and to identify the parameters associated with tumor recurrence.

Methods

The analysis included; age, sex, extent of resection, and radiologic and pathologic findings. Falcine meningiomas were classified by location as anterior, middle, or posterior as described for parasagittal meningiomas.

Results

Of the 795 meningioma patients treated between 1990 and 2004 at the authors'' institution, 68 patients with meningiomas arising from the falx underwent craniotomies. There were 22 male and 46 female patients (1 : 2.1). Mean age was 55 years and ranged from 14 to 77 years. Locations of falcine meningioma were; the anterior third in 33 cases, middle in 20, and posterior in 15. Mean tumor volume was 42 cc and ranged from 4 to 140 cc. In 58 of the 68 patients tumors were totally removed. Additional surgery for recurrence was performed in 6 patients over 15 years. Of these 6 patients, only two patients underwent gross total tumor resection at first operation; the other four underwent subtotal tumor resection. Based on pathologic reports, the largest tumor subtype was transitional. There were four patients with a high grade tumor-three atypical and one anaplastic meningioma. Of the 68 patients, 59 achieved a good outcome (no neurological deficit or recurrence), six had temporary complications, two suffered new permanent postoperative deficits, and the remaining one died due to severe brain swelling despite postoperative intensive care. Extent of surgical resection was found to be significantly related to tumor recurrence.

Conclusion

Falcine meningioma accounted for 8.5% of intracranial meningiomas and the transitional meningioma was the most common subtype of falcine meningioma. Gross total resection of tumor was the single most important predictor of an improved surgical outcome.     

NF2 gene expression in sporadic meningiomas: Relation to grades or histotypes real time‐PCR study

One of the most common regions involved in the meningiomas tumorigenesis is chromosome 22q where the NF2 gene resides. The deficiency or loss of the NF2 gene product, merlin/schwannomin, plays a role in tumor development and metastatization. Conflicting results have been reported on the prognostic value of merlin in meningiomas. Several studies have indicated NF2 gene inactivation as an early tumorigenic event unrelated to the histological grade or clinical behavior. On the contrary, the NF2 gene alteration rate differs between the different histotypes. A pathogenesis independent from the NF2 gene has been suggested in meningothelial meningiomas. In the present work, we studied the NF2 gene expression through real time‐PCR (RT‐PCR) in 30 meningiomas. The average of the NF2 gene expression of all meningiomas was considered as reference value. The average of expression of WHO grade I and II meningiomas was higher than the average of all meningiomas, whereas that of WHO grade III meningiomas was lower. When we compared the NF2 gene expression in the different meningioma grades we did not note a significant difference (P = 0.698) despite the tendency to decrease from grade I to grade III. The average expression of meningothelial meningiomas was higher than the reference value, and that of non‐meningothelial meningiomas was lower. The difference in NF2 gene expression between meningothelial and non‐meningothelial meningiomas was statistically significant (P = 0.013). Our data supports the finding that alterations in NF2 gene alteration are histotype related but not grade related.     

Invasive meningioma is associated with a low expression of E-cadherin and beta-catenin

Invasive meningioma shows benign histological features (WHO grade 1) and the brain expansion at the tumor-brain interface, and recurs more frequently than common meningiomas. To determine the mechanism of brain expansion, we studied the relationship between invasive meningioma and cell adhesion molecules. Immunostaining for E-cadherin (E-CH), N-cadherin (N-CH), beta-catenin, and Ki-67 was performed in 103 meningiomas that consisted of 61 meningothelial meningiomas, 25 fibrous meningiomas, 12 invasive meningiomas and 5 anaplastic meningiomas. All tumors were negative for N-CH. All the 61 meningothelial meningiomas, 10 of 12 invasive meningiomas, and 3 of 5 anaplastic meningiomas were positive for both E-CH and beta-catenin, while these were both negative in all of the fibrous meningiomas. In invasive meningiomas, the expansive part of the tumor showed a lower rate (4/12 tumors) of E-CH and beta-catenin positivity, while the central part showed a higher rate (10/12 tumors). The Ki-67 labeling index was higher in invasive and anaplastic meningiomas than in meningothelial meningiomas. These results suggest that a reduction in cell adhesion molecules and increased proliferative activity may be related, which may lead to a better understanding of the mechanism of meningioma expansion in the future.     

脑膜血管瘤病合并脑膜瘤临床病理及文献复习

目的 探讨脑膜血管瘤病(MA)合并脑膜瘤的临床病理特点.方法 回顾性分析1例颅内MA合并脑膜瘤病人的临床资料,行病理形态学观察及免疫组织化学检测,并对该病进行文献复习.结果 光镜观察:皮质内血管增生,脑膜上皮细胞及梭形的纤维母细胞样细胞围绕血管排列,部分大血管明显胶原化及透明变性,伴钙化或砂砾体形成,且可见明显的过渡型脑膜瘤成分,病灶内残留变性神经元和胶质细胞增生.免疫组化染色显示:vimentin阳性,上皮细胞膜抗原(EMA)局灶性阳性,Ki-67阳性率在脑膜瘤区域约为3％,在脑膜血管瘤病区则＜1％.结论 MA是--种少见的良性病变,病变通常位于大脑额颞叶皮质并可累及周围脑膜组织,MA合并脑膜瘤更少见,在形态学上应与侵袭性脑膜瘤、孤立性纤维瘤、颅内神经鞘膜瘤等鉴别.     

The origin of intracranial fibrosarcoma

Summary To elucidate the cellular derivation of intracranial fibrosarcoma, specimens from two cases of primary sarcoma and two cases of secondary, radiation-induced sarcoma in the cranium were examined by light and electron microscopy and histochemical techniques. The findings were carefully compared with those in four cases of benign fibroblastic meningioma. All the intracranial sarcomas examined in this study were localized on the cerebral surface and invaded the dura mater and brain.The histology of these tumors closely resembled that of fibrous fibrosarcoma described by Christensen and Lara [2]. The microscopic features of primary sarcomas were characterized by a spoke wheel arrangement of tumor cells, intercellular deposits of variable amounts of collagen fibers and the presence of many xanthoma cells. Secondary sarcomas presented tumor cells arranged in parallel interlacing bundles. An island of tumor tissue with the characteristics of benign meningioma was disclosed in a primary sarcoma. In meningioma was disclosed in a primary sarcoma. In electron micrographs, sarcoma cells showed ultrafine structures characteristic of meningothelial cells, including interdigitated cytoplasmic processes, desmosomes and/or half desmosomes, and abundant intracytoplasmic filaments. Basement membrane or an analogous substance, which is very unusual in the meningioma, were identified in some specimens of our primary sarcomas and fibroblastic meningioma. In the histochemical study, the activities of acid phosphatase and non-specific esterase showed no significant differences between the sarcoma cells and the meningioma cells.On the basis of morphological and histochemical findings, it is concluded in this study that fibrous fibrosarcomas in the cranium are of meningothelial derivation and therefore should be included in the category of malignant meningioma.     

Characteristics of cases with and without calcification in spinal meningiomas

PurposeTo quantify calcification in spinal meningiomas using Hounsfield unit (HU) values on CT, and to analyze the characteristics of cases with and without calcification and with different histologic subtypes.MethodsThe subjects were 53 patients who underwent surgical resection of spinal meningioma between January 1999 and December 2019. Clinical and surgical data were collected, and all patients were examined neurologically preoperatively and at final follow-up using the modified McCormick scale and the American Spinal Injury Association scale. Calcification was quantified on CT of the spine prior to surgery. A HU value >60 was considered to indicate calcification.ResultsThe 53 patients (11 males, 42 females) were aged 62.4 ± 14.3 (range 19 to 91) years at surgery, and had a symptom duration of 10.8 ± 9.0 (1–36) months. The histological type was meningothelial in 35 cases, psammomatous in 13, and others in 5. The mean tumor volume was 1166 ± 350 (593–2176) mm³, and the mean HU value was 212.2 ± 192.8 (43–648). Forty cases (75%) had calcification (HU value > 60). HU values were significantly related to duration of symptoms (R = 0.590, p < 0.05) and significantly higher in psammomatous cases (p < 0.05). Cases with calcification had longer operative times and greater blood loss, and a significantly lower rate of neurological improvement.ConclusionCT was effective for detecting calcification based on HU values. Detection of a HU value > 60 in spinal meningioma may be useful to narrow the differential diagnosis, evaluate the difficulty of resection, and improve intraoperative management, all of which may improve outcomes.     

Microcystic meningiomas: comparison of histology and computed tomography

INTRODUCTION: Microcystic meningiomas are defined by large vacuolated and stellate shaped cells. We recently examined a microcystic meningioma mimicking a malignant tumor on computed tomography (CT). The aim of the current study was to compare the radiological features of microcystic meningiomas with their histological patterns. METHODS: We have diagnosed 7 intracranial microcystic meningiomas among 204 meningiomas registered in the files of our Department of Pathology from 1994 to 2001. All CT scans performed before surgery were reviewed. RESULTS: Three of the microcystic meningiomas appeared as entirely microcystic tumors. Two of them were homogeneously hypodense or isodense on CT scan. The third mening was heterogeneous, containing some blood. The histologic pattern of the 4 other meningiomas showed microcystic tumor cells associated with meningothelial or fibrous tumor cells. These meningiomas were heterogeneous on CT scan. All meningiomas seemed to be connected to the dura mater. Three tumors were strongly and homogeneously enhanced after contrast media injection while 3 others were heterogeneously enhanced. No enhanced CT scan was available for 1 case. Astrocytomas were incorrectly diagnosed by CT scan in the 3 heterogeneously enhanced tumors. Meningiomas were correctly diagnosed in the 3 strongly enhanced tumors. CONCLUSION: The presence of microcystic tumour cells in meningiomas often results in erroneous diagnosis on CT scan, particularly for those which are heterogeneously enhanced. In these cases, a diagnosis of astrocytoma is often made.     

320排CT血管造影对窦旁脑膜瘤显微手术的指导意义

目的 评估320排CT血管造影(CTA)对窦旁脑膜瘤手术治疗的指导价值.方法 济南军区总医院神经外科自2008年5月至2010年8月对38例上矢状窦旁脑膜瘤患者术前行320排CTA检查,观察肿瘤血管与颅脑血管、肿瘤与颅骨的关系,指导肿瘤切除术.结果 320排CTA能清楚显示脑膜瘤的形态及其与邻近大血管、颅骨的三维关系和静脉窦的开放程度,38例患者均做到显微镜下全切除,其中SimpsonⅠ级26例,Ⅱ级12例,无手术死亡.术后出现暂时性偏瘫或原偏瘫加重8例,经治疗5例恢复正常.结论 320排CTA能提供脑膜瘤与邻近血管、颅骨和矢状窦的三维空间图像,为手术入路和术中矢状窦的处理提供有用信息,在窦旁脑膜瘤术前评估中有其独特的价值.

Abstract：

Objective To evaluate the clinical value of 320-row CT angiography (CTA) in the microsurgery of parasagittal meningiomas. Methods Thirty-eight patients with parasagittal meningiomas, admitted to our hospital from May 2008 to August 2010 and confirmed by CT and MR1,were examined with the 320-row CTA to observe the relations between tumor blood vessels and brain vessels, and between the tumor and the skull. Results The 320-row CTA provided clear three-dimensional images of the meningioma and its relations with the adjacent vessels and the skull. The condition of blood flow in the parasagittal sinus was shown and the proper surgical approach to remove the neoplasm was demonstrated. Simpson graded Ⅰ and Ⅱ resection was achieved in 26 and 12 patients,respectively. All the patients recovered well without postoperative deaths. Temporary paralysis or aggravated paralysis was noted in 8 after the operation and 5 of them recovered. Conclusion The 320-row CTA, being able to provide images of the parasagittal meningioma, and demonstrating its relations with the skull, adjacent vessels and sagittal sinus, can supply the vital information to choose the proper surgical approach and provide the useful message to manage the sinus during the operation, which has a great value in preoperative evaluation of the parasagittal meningioma.     

Ossified thoracic spinal meningioma in childhood: A case report and review of the literature

Spinal ossified meningiomas are extremely rare. This is a report of a study on a 15-year-old boy with thoracic spinal ossified meningioma. The meningioma was resected totally. Histopathological examination revealed a transitional meningioma (psammomatous+meningothelial). Immunohistochemically, Ki 67 antibody was applied but no positive staining was present. The surgical and pathological aspects of spinal ossified meningiomas were reviewed.     

The double immunostaining of CD133 and Ki-67 favours a significant co-localization pattern in fibroblastic subtype of meningiomas

BACKGROUND AND PURPOSE : A unique molecular and/or cellular marker for meningiomas, the most common intracranial tumours, has not been identified yet. MATERIAL AND METHODS: We investigated the co-localization fraction of CD133/Ki-67 in meningioma tissue array slide composed of 80 meningioma tissue samples of various histological variants. CD133 - a cell membrane stem cell marker - was previously proved to be associated with the initiation and progression of intracerebral gliomas and medulloblastomas. RESULTS : Immunohistochemical co-localization of CD133/Ki-67 was significantly higher in fibroblastic variant than in meningothelial and transitional subtypes. However, since there were only 3 atypical and 1 malignant meningioma spots in the tumour tissue array slide, it is difficult to draw a firm conclusion regarding the actual co-localization percentage and persistence of CD133/Ki-67 in atypical and malignant meningiomas. CONCLUSIONS : Far higher co-staining percentage of CD133/ Ki-67 in fibroblastic meningioma samples compared to meningothelial subtype, a histological meningioma variant, architectonically resembling the non-neoplastic meningeal cells, gave us the impression that CD133 may play a role in the formation and progression of fibroblastic meningioma variants. The persistency and the validity of this finding need to be verified by further histopathological and molecular research in order to clarify the possible role of CD133 in meningiogenesis.     

脑膜瘤全切除术后复发的组织病理学因素分析

目的 通过对患者的年龄、性别、脑膜瘤组织学分型及分级等因素的分析,了解它们与肿瘤复发间的关系.方法 56例脑膜瘤标本分为复发组(n=30)、初发组(n=26),对全部病理标本进行组织学分级,统计学分析组织学分级与肿瘤复发之间的关系.结果 复发组上皮型17例(56.67%),纤维型7例(23.33%),两型比较,P＜0.05.复发组组织病理学分级Ⅱ级、Ⅲ级者比率显著高于初发组(P＜0.01).患者的年龄、性别2组对比差异无统计学意义(P＞0.05).结论 脑膜瘤复发在组织病理学分型上以上皮型居多,脑膜瘤组织学分级越高复发率越高.     

Clinical Implications of the Mitotic Index as a Predictive Factor for Malignant Transformation of Atypical Meningiomas

ObjectiveIntracranial atypical meningiomas have a poor prognosis and high rates of recurrence. Moreover, up to one-third of the recurrences undergo high-grade transformation into malignant meningiomas. We aimed to investigate the clinical factors that can predict the propensity of malignant transformation from atypical to anaplastic meningiomas. MethodsBetween 2001 and 2018, all patients with atypical meningioma, in whom the tumors had undergone malignant transformation to anaplastic meningioma, were included. The patients’ medical records documenting the diagnosis of atypical meningioma prior to malignant transformation were reviewed to identify the predictors of transformation. The control group comprised 56 patients with atypical meningiomas who were first diagnosed between January 2017 and December 2018 and had no malignant transformation. ResultsNine patients in whom the atypical meningiomas underwent malignant transformation were included. The median time interval from diagnosis of atypical meningioma to malignant transformation was 19 months (range, 7–78). The study group showed a significant difference in heterogeneous enhancement (77.8% vs. 33.9%), bone invasion (55.6% vs. 12.5%), mitotic index (MI; 14.8±4.9 vs. 3.5±3.9), and Ki-67 index (20.7±13.9 vs. 9.5±7.1) compared with the control group. In multivariate analysis, increased MI (odds ratio, 1.436; 95% confidence interval, 1.127–1.900; p=0.004) was the only significant factor for predicting malignant transformation. ConclusionAn increased MI within atypical meningiomas might be used as a predictor of malignant transformation. Tumors at high risk for malignant transformation might require more attentive surveillance and management than other atypical meningiomas.     

Surgical management of falcine meningiomas: Experience of 95 patients

Falcine meningiomas, defined as a meningiomas arising from the falx not involving the superior sagittal sinus, account for 9% of all intracranial meningiomas. We analyzed 95 patients with falcine meningiomas who underwent surgical removal of their lesion at our institution between 2001 and 2014. Surgical management of these patients, focusing on anatomical and clinical features is described. Thus, based on our series, a surgical algorithm, classifying the falcine meningioma into four types, according to location at the falx, and using an ipsilateral interhemispheric approach in supine or prone position, is described. The median length of follow-up was 7.1 years (range 1.6–12.3 years). Approximately one-third of all patients was asymptomatic, headaches occurred in 27 patients, seizures in 14 cases, and lower-extremity weakness in 9 cases. In this series, the middle third of the falx was the most frequently involved site (55,78%), while the anterior third (26,31%) and the posterior type (17,89%) were less common. The transitional and meningothelial types occurred in 69 of patients and a high grade in only two patients. Compared with previous series in literature, there was no mortality and Gross Total Resection was obtained in 83 (87,5%) cases. Three of 95 patients experienced new or worsened neurological deficits after surgery while other complications were relatively in only 6 cases. This study presents our good results about removal of the tumor while preserving major cortical veins and the sinus using advanced microsurgical tools.     

Papillary meningioma: an aggressive variant meningioma with clinical features and treatment: a retrospective study of 10 cases

Introduction: Papillary meningioma is a rare subtype of malignant meningiomas. The aim of this retrospective study was to investigate the clinical, radiological, histopathological features and prognosis for papillary meningioma at our institutions. Materials and methods: Ten patients with clinically, radiologically and histopathologically confirmed papillary meningiomas were treated at our hospitals. The clinical data, imaging characteristics, histopathological features, surgical treatment and postoperative follow-up, were analyzed retrospectively. Results: The patients with a mean age of 36.9 years at the time of their initial operations. The papillary meningiomas were predominantly located in the convexity (n = 6). At their initial operation, six patients underwent gross total resection and four patients underwent subtotal resection. The mean post-operative follow-up period was 42.6 months (range: 12–90 months). Six patients underwent multiple surgical resections. The mean time to first recurrence was 21.5 months. On magnetic resonance imaging scan, marked enhancements and dural tail signs were displayed in all lesions. All lesions showed peritumoral edema. Cysts were seen in four lesions. Bone hyperostosis or destruction was seen in six lesions. Cerebrospinal fluid dissemination was seen in three lesions. Incomplete surgical resection was associated with recurrence. MIB-1 labeling index was associated with progression-free survival for patients (p = 0.0442). Conclusions: Papillary meningioma has a tendency to present in middle-aged patients, and it has specific clinical and histopathological characteristics. MIB-1 labeling index and the extent of resection might predict the recurrence. Cystic formation, peritumoral edema, osseous change and CSF dissemination might be neuroimaging characteristics of papillary meningioma, especially in recurrence papillary meningioma.