Cystic meningioma: radiological, histological, and surgical particularities in 43 patients

Conventional and advanced MR imaging findings of primary Ewing sarcoma of the tentorium: a case report with literature review

BACKGROUND

Primary intracranial Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is an extremely uncommon tumor. Care should be taken as it can be mistaken for a meningioma radiologically.

CASE DESCRIPTION

This paper reports a case of a 44-year-old male presenting with headache. A magnetic resonance imaging demonstrated a mass involving the tentorium, cerebrum and cerebellum with solid-cystic component. The solid component was hyperintense on T1-weighted images with significant enhancement. There was restriction in diffusion-weighted images and microhemorrhagic signal change in susceptibility weighted images. MR perfusion revealed increased relative cerebral blood volume and mean transit time values. Surgical pathology was reported as ES.

CONCLUSIONS

Intracranial ES/pPNET is a rare tumor that generally arises from the meninges. It must be distinguished from meningioma since it can be mistaken radiologically, because the treatment and prognosis are quite different. Localization and conventional MR signal characteristics of both lesions are similar. Whereas, MR perfusion findings may be helpful in discrimination.

5-aminolevulinic acid fluorescence guided surgery for resection of cystic meningioma with bone invasion

Meningiomas have a 5 year recurrence rate of 8%. Histological grade and extent of resection are the two main prognostic factors. Cystic meningiomas represent between 2 and 4% of meningiomas, and the complete resection rate in these cases is 62.7%. 5-ALA has been shown to be useful in detecting tumour remnants that could go unnoticed by the conventional microsurgical technique, thereby achieving more complete resections. We present the case of a 66-year-old patient with a frontal convexity meningioma, presenting with a cystic component and bone invasion, who was treated using 5-ALA fluorescence-guided surgery. Fluorescence emission from the tumour tissue allowed the areas of bone invasion and the cystic wall to be identified, achieving complete resection.

Sclerosing meningioma with a large peritumoral cyst: Case report

Meningioma morphology is diverse. Although unlisted in the WHO classification, sclerosing meningioma is a rare variation featuring an extremely low signal intensity on MRI T2-weighted imaging. About 50 cases of sclerosing meningiomas, including spinal tumors, have been reported; however, cases with an accompanying large peritumoral cyst remain unreported. Here, we first report a rare case of sclerosing meningioma with a large peritumoral cyst and review relevant literature.

Review of meningioma diagnosis and management

Meningiomas are the most common intracranial tumors in adult patients. Although the majority of meningiomas are diagnosed as benign, approximately 20% of cases are high-grade tumors that require significant clinical treatment. The gold standard for grading central nervous system tumors comes from the World Health Organization Classification of Tumors of the central nervous system. Treatment options also depend on the location, imaging, and histopathological features of the tumor. This review will cover diagnostic strategies for meningiomas, including 2021 updates to the World Health Organization's grading of meningiomas. Meningioma treatment plans are variable and highly dependent on tumor grading. This review will also update the reader on developments in the treatment of meningiomas, including surgery, radiation therapy and monoclonal antibody treatment.

The Performance of Different Machine Learning Algorithm and Regression Models in Predicting High-Grade Intracranial Meningioma

Meningioma is the most common primary tumor of the central nervous system (CNS). Individualized treatment strategies should be formulated for the patients according to the WHO (World Health Organization) grade. Our aim was to investigate the effectiveness of various machine learning and traditional statistical models in predicting the WHO grade of preoperative patients with meningioma. Patients diagnosed with meningioma after surgery in West China Hospital and Shangjin Hospital of Sichuan University from 2009 to 2016 were included in the study cohort. As the training cohort (n = 1975), independent risk factors associated with high-grade meningioma were used to establish the Nomogram model. which was validated in a subsequent cohort (n = 1048) from 2017 to 2019 in our hospital. Logistic regression (LR), XGboost, Adaboost, Support Vector Machine (SVM), K-Nearest Neighbor (KNN), and Random Forest (RF) models were determined using F1 score, recall, accuracy, the area under the curve (ROC), calibration plot and decision curve analysis (DCA) were used to evaluate the different models. Logistic regression showed better predictive performance and interpretability than machine learning. Gender, recurrence history, T1 signal intensity, enhanced signal degree, peritumoral edema, tumor diameter, cystic, location, and NLR index were identified as independent risk factors and added to the nomogram. The AUC (Area Under Curve) value of RF was 0.812 in the training set, 0.807 in the internal validation set, and 0.842 in the external validation set. The calibration curve and DCA (Decision Curve Analysis) indicated that it had better prediction efficiency of LR than others. The Nomogram preoperative prediction model of meningioma of WHO II and III grades showed effective prediction ability. While machine learning exhibits strong fitting ability, it performs poorly in the validation set.

Cystic lesions in giant intraventricular meningioma: Two case reports

RATIONALE

Giant meningioma stemming from the intraventricular zone has been reported to be extremely few. Two cases of supersize (>8 cm) intraventricular meningiomas presenting with cystic lesions and their clinical characteristics were collected in our study.

PATIENT CONCERNS

One patient was a 56-year-old man who was hospitalized for blunt headache and weakness of the right lower limb along with a defect of the right visual field for 12 months. The other patient is a 22-year-old lady who presented with a slight headache accompanied by right facial numbness for 1 week. None of them had a significant past medical history.

DIAGNOSES

Computed tomography and magnetic resonance imaging of both patients revealed a giant heterogeneous, enhancing tumor mainly in the left trigonum with low-density or hypointense cystic lesions located within or around the tumor. The pathological and immunohistochemical staining indicated fibroblastic meningioma (case 1) and atypical meningioma (case 2) respectively, thus the patients' diagnoses were confirmed.

INTERVENTIONS

Total microsurgical resection, including the cystic wall, was performed via a transcortical (transtemporoparietal occipital) approach in both patients, and a ventricular drainage tube was placed for 24 to 48 hours routinely after removed the tumor.

OUTCOMES

Postoperatively, both patients recovered free from episodes of symptoms, and imaging examinations confirmed no evidence of regrowth of the meningioma during an average 24 months follow-up.

LESSONS

Cystic lesions may indicate the histopathologic malignancy of intraventricular meningioma. Transcortical approach through the posterior temporal lobe or the parieto-occipital lobe is an effective technology for giant intraventricular meningiomas.

Lesion delineation framework for vestibular schwannoma, meningioma and brain metastasis for gamma knife radiosurgery using stereotactic magnetic resonance images

BACKGROUND AND OBJECTIVE

GKRS is an effective treatment for smaller intracranial tumors with a high control rate and low risk of complications. Target delineation in medical MR images is essential in the planning of GKRS and follow-up. A deep learning-based algorithm can effectively segment the targets from medical images and has been widely explored. However, state-of-the-art deep learning-based target delineation uses fixed sizes, and the isotropic voxel size may not be suitable for stereotactic MR images which use different anisotropic voxel sizes and numbers of slices according to the lesion size and location for clinical GKRS planning. This study developed an automatic deep learning-based segmentation scheme for stereotactic MR images.

METHODS

We retrospectively collected stereotactic MR images from 506 patients with VS, 1,069 patients with meningioma and 574 patients with BM who had been treated using GKRS; the lesion contours and individual T1W+C and T2W MR images were extracted from the GammaPlan system. The three-dimensional patching-based training strategy and dual-pathway architecture were used to manage inconsistent FOVs and anisotropic voxel size. Furthermore, we used two-parametric MR image as training input to segment the regions with different image characteristics (e.g., cystic lesions) effectively.

RESULTS

Our results for VS and BM demonstrated that the model trained using two-parametric MR images significantly outperformed the model trained using single-parametric images with median Dice coefficients (0.91, 0.05 versus 0.90, 0.06, and 0.82, 0.23 versus 0.78, 0.34, respectively), whereas predicted delineations in meningiomas using the dual-pathway model were dominated by single-parametric images (median Dice coefficients 0.83, 0.17 versus 0.84, 0.22). Finally, we combined three data sets to train the models, achieving the comparable or even higher testing median Dice (VS: 0.91, 0.07; meningioma: 0.83, 0.22; BM: 0.84, 0.23) in three diseases while using two-parametric as input.

CONCLUSIONS

Our proposed deep learning-based tumor segmentation scheme was successfully applied to multiple types of intracranial tumor (VS, meningioma and BM) undergoing GKRS and for segmenting the tumor effectively from stereotactic MR image volumes for use in GKRS planning.

Unusual imaging characteristics of cystic meningioma in cerebellopontine angle

We report a case of cystic meningioma at the left cerebellopontine angle (CPA). Magnetic resonance imaging demonstrated both solid and cystic components in the tumor. The cystic component appeared slightly hyperintense compared to cerebrospinal fluid on fluid-attenuated inversion recovery (FLAIR) imaging. A hypointense tubular structure was identified in the cystic component on 3D driven equilibrium sequencing. These imaging findings are unusual for cystic meningioma. However, awareness of these unusual imaging features is important to determine appropriate treatment strategies although cystic meningioma at the CPA is extremely rare.

Clinical features, radiological findings, and prognostic factors for primary intracranial chordoid meningioma

OBJECTIVES

Chordoid meningioma (CM) is an infrequent histologic subtype of meningiomas. Owing to its low occurrence, this subtype has been rarely described. Our subject was to explore the clinical features, radiological characteristics, and prognostic factors of primary intracranial chordoid meningioma.

METHODS

We reviewed the medical records and collected follow-up information of 34 cases who had been surgically treated and histologically diagnosed with CM at the Department of Neurosurgery, West-China Hospital of Sichuan University, from January 2009 to December 2021.

RESULTS

Among all 7,950 meningioma cases, the proportion of primary intracranial CM was 0.43% (34/7,950). The median diagnosis age was 47 (ranging from 12 to 74) and the gender ratio (male to female) was 2.1:1. For radiological features, heterogeneous enhancement, skull base, and ventricular localization, cystic degeneration and dural tail sign were common in CM cases. In treatment, gross total resection (GTR) was achieved in 22/34 cases (64.7%) and subtotal resection (STR) was achieved in 12/34 cases (35.3%). Further, 11/34 patients (32.4%) had received postoperative adjuvant radiotherapy (RT). The follow-up duration ranged from 4 to 157 months after operation. The progression rate was 20.7% (6/29) and the median of PFS was 38 months. By survival analysis, accepting adjuvant radiotherapy and achieving GTR were correlated with longer progression-free survival for prognosis.

CONCLUSION

CM is a rare subtype of meningiomas. In our series, it mainly involved adults and did not show a predilection for women compared with meningiomas in general. For a better prognosis, gross total resection and postoperative adjuvant radiotherapy are recommended. Nevertheless, due to the restriction of the series sample, patients lost for follow-up and inherent biases of a retrospective study, more cases and a shorter follow-up duration are needed for better management of chordoid meningioma.

Multiple ossified spinal meningiomas in the thoracic spine: A case report and literature review

Background

Ossified spinal meningioma (OSM) is a rare form of a spinal tumor. The surgical strategies and pathologic findings related to OSM have been investigated in recent years. However, multiple OSMs are rarely reported. Here, we intend to present a rare case of multiple OSMs and review the relevant published literature.

Case Presentation

A 76-year-old woman experienced a progressive sensorimotor disturbance in her bilateral lower limbs for the past 2 years. She complained of inability to walk, urinary incontinence, and chronic constipation when referred to our hospital. A neurological examination revealed a diminished sensation below the bilateral T7, and her neurological status was Nurick Grade 6. Magnetic resonance imaging (MRI) revealed multiple intradural-extramedullary neoplasms at the T7-T11 level. Computed tomography (CT) scans showed five high-density masses of varying sizes in the spinal canal at the T7-T12 level. The patient underwent tumor resection through T7-T11 laminectomy. A histopathological examination revealed multiple OSMs.

Conclusion

We reported a rare case of multiple OSMs in an elderly patient. After one-stage complete resection, the patient recovered with satisfactory curative effect. Although elderly patients will face various postoperative complications due to their poor physical condition, we still recommend one-stage complete resection of multiple OSMs to reduce recurrence.

Case report and literature review: Treatment of multiple meningiomas combined with multiple unruptured aneurysms in a single operation

Background

Although the incidence of a single meningioma or a single aneurysm is common, cases of multiple meningiomas combined with multiple aneurysms are rarely reported, and surgical treatment of the coexisting situation is also relatively uncommon.

Case presentation

A 38-year-old male patient presented to the neurosurgery department of our center with a headache. Examination revealed only symptoms of headache. Laboratory tests showed only decreased total protein and albumin. Magnetic resonance imaging showed preoccupation with the frontal lobe and the right temple bone. Magnetic resonance angiography and digital subtraction angiography showed two aneurysms in the anterior communicating artery and right anterior cerebral artery. Based on a combination of the patient’s history and imaging, we hypothesized that the patient was simultaneously suffering from meningioma and an aneurysm, and both of them are multiple. The patient underwent tumor resection and clipping procedure based on this hypothesis in one surgery. Intraoperative biopsy proved to be a meningioma. The patient was discharged on the 10th postoperative day, and a postoperative follow-up suggested no complications.

Conclusion

Multiple meningiomas combined with multiple aneurysms are rare to be reported in the same patient. For those unruptured intracranial aneurysms (UIAs) located in the visual field of craniotomy prepared for brain tumorlike meningioma, it is possible to do the clipping as well. When the meningiomas are multiple, fitted with the surgical indication, and located in a position that cannot be treated in one surgery, this may lead to a two-stage operation, no matter where the UIAs are located.

Outcomes following surgical resection of cystic intracranial meningiomas

INTRODUCTION

Cystic meningiomas are rare, accounting for 2-7% of all intracranial meningiomas. Little is known regarding whether these meningiomas behave differently compared to solid meningiomas. We sought to study this relatively uncommon imaging appearance of meningioma and to evaluate its clinical significance.

METHODS

A single-institution retrospective cohort study of surgically-treated meningioma patients between 2000 and 2019 was conducted. Cystic meningioma was defined as a tumor with an intratumoral or peritumoral cyst present on preoperative imaging. Demographics, preoperative imaging, histopathology characteristics, operative data, and surgical outcomes were reviewed. Imaging variables, histopathology and outcomes were reported for cystic meningiomas and compared with non-cystic meningiomas. Univariate/multivariable analyses were conducted.

RESULTS

Of 737 total meningiomas treated surgically, 38 (5.2%) were cystic. Gross total resection (GTR) was achieved in 84.2% of cystic meningioma patients. Eighty-two percent of cystic meningiomas were WHO grade I (n = 31), 15.7% were grade II and 2.6% were grade III. Most cystic meningiomas had low Ki-67/MIB-1 proliferation index (n = 24, 63.2%). A total of 18.4% (n = 7) patients with cystic meningioma had recurrence compared to 12.2% (n = 80) of patients with non-cystic meningioma (p = 0.228). No significant difference in median time to recurrence was observed between cystic and non-cystic meningiomas (25.4, Q1:13.9, Q3:46.9 months vs. 13.4, Q1:8.6, Q3:35.5 months, p = 0.080).

CONCLUSIONS

A small portion of intracranial meningiomas have cystic characteristics on imaging. Cystic meningiomas are frequently WHO grade I, have low proliferation index, and had similar outcomes compared to non-cystic meningioma. Cysts in meningioma may not be a surrogate to determine aggressive meningioma behavior.

Risk Factors of Postoperative Meningitis in Lateral Ventricular Trigone Meningiomas: A Clinical Analysis of 64 Patients

Purpose

Patients with intraventricular tumors are more susceptible to postoperative meningitis (POM) than other intracranial tumors. In this study, we explored the risk factors of POM in lateral ventricular trigone meningiomas (LVTMs).

Methods

Clinical features of 64 patients with LVTMs were analyzed. Age, gender, body mass index, medical history, intraoperative blood loss (IBL), intraventricular drainage placement, surgical duration, tumor grade, postoperative tumor cavity hemorrhage, and tumor size were included in univariate and multivariate analyses of POM.

Results

Of the 64 patients, 14 patients (21.9%) received diagnosis of POM. The univariate analysis revealed IBL ≥400 mL (odds ratio [OR], 9.012; p = 0.003), tumor size ≥50 cm³ (OR, 3.071; p = 0.080), and surgical duration ≥5 h (OR, 2.970; p = 0.085) were considered possible risk factors for POM (p < 0.10). Tumor size (R = 0.514) and surgical duration (R = 0.624) were significantly correlated with IBL (p < 0.05). In the multivariate analysis, only IBL was found to be an independent risk factor for POM.

Conclusion

The IBL ≥400 mL is independently associated with the increased risk of POM in LVTM patients. Our results demonstrate the importance of controlling IBL for preventing POM, especially in large tumors and long surgeries.

A large cystic meningioma incidentally detected during general examination for breast cancer

A 57-year-old woman who underwent needle biopsy for a subcutaneous mass in the breast was diagnosed with invasive ductal carcinoma. General examination incidentally revealed an intracranial tumor. At presentation, the patient showed memory disturbance but no focal neurological deficits. Cranial computed tomography (CT) revealed a large, hypodense cyst in the left frontotemporal region, involving a tumor with extensive hyperostotic changes in the left sphenoid and frontal bones. Magnetic resonance imaging showed that the tumor was attached to the dura mater of the pterional region and extensively enhanced, with involvement of the frontal and sphenoid bones. The less vascular tumor was removed en bloc by drilling the affected sphenoid and frontal bones as much as possible. The microscopic findings of the tumor were consistent with meningothelial meningioma with invasion into the dura mater and bone. Cystic meningioma should be considered when encountered with a dural-based cystic tumor, even in patients with cancer. In such circumstances, prompt and preferential resection may be indicated for intracranial tumors for timely initiation of the long-term treatment of cancer.

Intracranial solitary fibrous tumor/hemangiopericytoma mimicking cystic meningioma: A case report and literature review

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a relatively rare type of tumor that originates from meningeal mesenchyme. A 30-year-old man presented leaning his body to the left and with weakness of his left lower limb. Computed tomography revealed a heterogeneous mass with multiple cystic components and hyperostosis of the right cranial convexity. Magnetic resonance imaging showed the mass was broadly attached to the dura matter with dural tail sign. In addition, the lesion had extensive cystic degeneration and a solid compartment showing low apparent diffusion coefficient values. The patient underwent gross total resection of the intracranial lesion and presented no recurrence within a 12-month follow-up period. Histopathology confirmed SFT/HPC (World Health Organization grade Ⅱ). Although there have been several useful techniques reported to differentiate SFT/HPC from meningioma, in this case the atypical findings for SFT/HPC made it difficult. We report the imaging findings of this case and some literature reviews.

Pre-operative imaging and post-operative appearance of standard paediatric neurosurgical approaches: a training guide for neuroradiologists

A short-cut narrative review was conducted according to the SANRA guidelines to identify studies describing normal and abnormal postoperative radiological features of the most common paediatric neurosurgical procedures. Rather than focusing on the original pathology addressed by neurosurgical means, this review explored three main areas of operative neurosurgery: ventricular access, supratentorial & infratentorial craniotomies, and posterior fossa/craniocervical junction decompression. A total of twenty-three landmark papers were included for review based on their relevance to address the research question and serve as a practical guide for paediatric neuroradiology trainees and fellows. Accurate in text referencing of the ClinicalTrials.gov identifier, and weblink, has also been provided for all trials discussed in the results section. All the above is complemented by relevant iconography meant to describe a wide range of postoperative changes and early complications. Finally, the review is enriched by a discussion touching upon haemostatic agents, intentionally retained foreign bodies and the future of machine learning for neuroradiology reporting. Overall, the information presented in a systematic fashion will not only help trainees and fellows to deepen these topics and expand their knowledge in preparation for written and oral boards, but will also represent a useful resource for everyone including trained neuroradiologists and neurosurgeons themselves.

Differentiating between spinal schwannomas and meningiomas using MRI: A focus on cystic change

Objectives

To retrospectively determine the diagnostic ability of MRI in differentiating between intradural extramedullary spinal schwannomas and meningiomas.

Methods

A total of 199 patients with spinal intradural extramedullary tumors who underwent preoperative contrast-enhanced MRI between January 2012 and December 2018 were included in this study. Two radiologists independently analyzed the presence of cystic change, dural tail sign, and neural foraminal extension. Clinical and MRI features between the two groups were compared by univariable and multivariable analyses using logistic regression. Interobserver agreements were calculated using kappa statistics.

Results

Patients with schwannoma showed significantly higher frequency of cystic change (96% vs 24%, P < 0.001), neural foraminal extension (29% vs 3%, P = 0.001), and lumbar location (41% vs 5%, P = 0.008). Patients with meningioma showed significantly higher frequency of dural tail sign (64% vs 1%, P < 0.001), thoracic location (75% vs 31%, P = 0.007), older age (59.7 years vs 47.6 years, P < 0.001), higher female predominance (83% vs 50%, P < 0.001), and smaller size (19.8 cm vs 28.8 cm, P < 0.001). Multivariable analysis showed that cystic change (P < 0.001; odds ratio [OR], 0.02), dural tail sign (P < 0.001; OR, 36.23), age (P = 0.032; OR, 1.06), and lumbar location (P = 0.006; OR, 0.02) were independent factors. Interobserver agreements were almost perfect for all analyses.

Conclusions

MRI features were useful in differentiating between intradural extramedullary schwannomas from meningiomas. The presence of cystic change and dural tail sign were independently significant discriminators.

Modern day imaging of meningiomas

Meningiomas are the most common primary tumors of the central nervous system and as such they are often encountered at neuroimaging. Fortunately, meningiomas are readily diagnosed with anatomic computed tomography and magnetic resonance imaging. While conventional imaging is the mainstay for initial diagnosis and delineating tumor for treatment planning and posttreatment follow-up, the last couple of decades have given rise to advanced physiologic and metabolic imaging techniques that serve as powerful tools in the management of meningioma. These modern approaches are allowing imaging to expand its utility to include extraction of biologic and potentially prognostic information that will ultimately improve care for meningioma patients.

Primary Gliosarcoma of the Cerebellum in a Young Pregnant Woman: Management Challenges and Immunohistochemical Features

Background

Gliosarcoma (GS) represents a rare, high-grade (WHO Grade IV), central nervous system neoplasm, characterized by a very poor prognosis. Similar to other high-grade gliomas, GS affects mainly adults in the 5^th-7^th decade of life and presents a higher incidence in males. The most reported locations of GS are the temporal lobe and the frontal lobe, while only eight cases of GS originating from the posterior cranial fossa are reported in the literature.

Case Description

We report the first case occurring during pregnancy in a 33-year-old patient. Diagnosis was obtained on the 15^th week of gestation when patient presented with signs and symptoms of life-threatening raised intracranial pressure. Surgical excision was followed by early recurrence and eventually disease progression because the patient refused adjuvant treatment to save her fetus.

Conclusions

GS should be considered in the differential diagnosis of posterior cranial fossa tumors with radiological features of meningioma or glioblastoma, even in young patients. To this regard, sarcomas, solitary fibrous tumors, and even metastases should be considered, especially in light of the tendency of GS to give rise to extracranial localizations. Whenever an aggressive management with radical excision and adjuvant treatment is not safely achievable, disease progression is likely to be unavoidable.

Prediction of High-Grade Histology and Recurrence in Meningiomas Using Routine Preoperative Magnetic Resonance Imaging: A Systematic Review

OBJECTIVE

Estimating the risk of recurrence after surgery remains crucial during care of patients with meningioma. Numerous studies identified correlations of characteristics on routine preoperative magnetic resonance imaging (MRI) with postoperative recurrence or high-grade histology but showed partially inconclusive results.

METHODS

A systematic review of the literature was performed about findings on preoperative MRI and their correlation with high-grade histology and recurrence. Quality of the included studies was analyzed using standardized Quality Assessment of Diagnostic Accuracy Studies criteria.

RESULTS

Among the 35 studies included, quality of the series according to the Quality Assessment of Diagnostic Accuracy Studies criteria differed widely. Remarkably, MRI variables found to be associated with high-grade histology were commonly not consistently associated with prognosis and vice versa. Correlations of the tumor size, the peritumoral edema size, and contrast-enhancement of the tumor capsule with high-grade histology were controversial. In most studies, non-skull base tumor location, cyst formation, heterogenous contrast-enhancement, an irregular tumor shape, and disruption of the tumor/brain border but not intensity of the lesion on T2-weighted images, calcifications, or bone involvement were associated with grade II/III histology. Although tumor and edema size were usually found to correlate with recurrence, heterogenous contrast enhancement, cyst formation, intensity of the tumor on T2-weighted MRI, and enhancement of the tumor capsule were mostly not related with progression.

CONCLUSIONS

Several mostly consistent but partially inconsistent variables associated with high-grade histology or prognosis were identified. Although standardized studies are needed to provide further clarification, consideration of these findings can help to improve estimation of prognosis and can therefore improve postoperative care in patients with meningioma.

Intracranial cystic meningiomas: A series of six patients

OBJECTIVE

Although 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 METHODS

Six 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.

RESULTS

All 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 560nm 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).

CONCLUSION

It 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 560nm 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.

A case report on cystic meningioma in cerebellopontine angle and recommendations for management

RATIONALE

Cystic meningioma located at the cerebellopontine angle (CPA) is an extremely rare occurrence. It is frequently misdiagnosed preoperatively. Little is known about the clinical features and outcome of this rare disease.

PATIENT CONCERNS

A 70-year-old male presenting with progressive headache and gait disturbance.

DIAGNOSIS

According to the symptoms, signs, and Gd-enhanced magnetic resonance images (MRI), a preoperative diagnosis of hemangioblastoma located in left CPA was made. Finally, the histological examination revealed a meningioma.

INTERVENTIONS

A complete resection, including the part of the solid mass together with cyst, was performed.

OUTCOMES

The postoperative course of the patient was uneventful, and no residual or recurrent tumor was found during the 24-month follow-up period.

LESSONS

Cystic meningioma should be included in the differential diagnosis of a CPA mass with atypical radiologic features, such as a large cyst and enhanced mural nodule. By summarizing the related literature, we found that the most common pathological subtype of CPA cystic meningioma is the clear cell subtype, which belongs to WHO grade II. Gross total resection including the enhanced cyst wall is extremely important. A close follow-up is necessary because of the high recurrence rate in this subset of meningioma.

Meningioma mimicking an intraparenchymal cystic tumor

Meningiomas rarely exhibit cystic lesions with mural nodules, and may be misdiagnosed as intraparenchymal cystic tumors. We herein present a 64-year-old woman with a cystic lesion and enhancing mural nodule in the left temporal lobe accompanied by peritumoral brain edema. Differential diagnoses included low-grade gliomas, hemangioblastoma, and cystic meningioma. Gross total resection of the tumor was achieved through a temporal surgical approach. Intraoperative findings showed that the tumor was an extraparenchymal tumor. The cyst was covered by an extraparenchymal thin membrane and the cystic fluid was yellowish in color. The final result of the pathological examination was microcystic meningioma, WHO grade I. Although intraparenchymal tumors, such as hemangioblastoma, ganglioglioma, pilocytic astrocytoma, and pleomorphic xanthoastrocytoma, commonly display this MRI pattern, meningioma needs to be included in the differential diagnosis.

Differentiating spinal intradural-extramedullary schwannoma from meningioma using MRI T2 weighted images

OBJECTIVE:

Prior studies advocate the subjective visual differences between meningioma and schwannoma on T₂ weighted images, however objective measurement of signal intensity differences may be useful in certain cases. The aim of this study was to investigate whether an objective evaluation of SIs on T₂ weighted images would be useful to differentiate spinal schwannomas from meningiomas.

METHODS:

The patients with spinal MRIs demonstrating path proven and subsequently treated intradural extramedullary spinal tumors were selected between April 2008 and May 2017. Regions of interest (ROIs) were measured in the tumor and subcutaneous fat on the same image, and we calculated the SI ratio between tumor and fat ROIs.

RESULTS:

Twenty patients each with meningioma and schwannoma were enrolled. The SI ratios of schwannomas were significantly higher than those of meningiomas (both researcher 1 and 2: p = 0.002). The areas under the curve by researchers 1 and 2 were 0.780. The cutoff value of SI ratio by both of researchers 1 and 2 to differentiate between schwannomas from meningiomas was 0.420 (sensitivity: 80.0%, specificity: 70.0-75.0%).

CONCLUSION:

The SI ratio, calculated from the SIs of the tumor and fat on T₂ weighted images, is useful for differentiating spinal schwannomas from meningiomas to obtain an accurate diagnosis.

ADVANCES IN KNOWLEDGE:

Signal intensity ratio of the spinal tumor and fat on T₂ weighted images is useful for differentiating schwannomas from meningiomas to obtain an accurate diagnosis.

Characteristic features and proposed classification in 69 cases of intracranial microcystic meningiomas

Microcystic meningioma (MM) is a rare subtype of intracranial meningiomas, with clinical and radiologic features not well characterized in the literature. Based on our experience, we propose a classification system of intracranial MMs. We reviewed the medical records, radiographic studies, and operative notes of a group of consecutive patients with intracranial MM. The mean age of the 69 patients was 46.8 ± 10.6 years (range, 21-75 years). Three types of intracranial MMs could be identified. Type 1 MMs presented as a solid lesion, hypointense or isointense on T1WI, hyperintense on T2WI, and homogeneous or heterogeneous enhancement, and were found in 43 patients (67.2%). Type 2 MMs represented signals similar to CSF both on T1WI and T2WI, and faint reticular enhancement with marginal enhancement, and these were found in 7 patients (10.9%). Type 3 MMs consisted of cystic-solid or cystic lesion and were found in 14 patients (21.9%). Significant differences were observed among the different types of MMs for the following variables: sex, presence of severe peritumoral brain edema (PTBE), and extent of tumor resection. Females were found in all of patients with type 2 MMs, but were only 35.7% of those with type 3 MMs (P = 0.018). Severe PTBEs were more common among patients with type 1 MMs (55.8%) than among those with type 2 (14.3%) and type 3 MMs (14.3%) (P = 0.007). Type 1 MMs (97.7%) were associated with a significantly higher rate of gross total resection compared with the other two types (71.4 and 78.6%) (P = 0.019). Total length of hospital stay after craniotomy ranged from 4 to 30 days (median, 8 days). There were no significant differences in progression-free survival among the three types of MMs (P = 0.788). The current classification identifies three distinct types of intracranial MM based on their radiological findings and growth patterns. The type 1 MMs are more commonly associated with severe PTBE. Type 2 and Type 3 MMs have a higher predilection towards parasaggital location with venous involvement and therefore have a lower rate of gross total resection.

Cystic Meningiomas: Correlation between Radiologic and Histopathologic Features

Background

Tumors with cysts often correlate with gliomas, metastatic tumors, or hemangioblastomas, which require differentiation.

Methods

Thirty-eight cases of cyst associated-meningioma based on preoperative radiologic studies and histologic confirmations were reviewed from November 1998 to July 2017.

Results

A total of 395 cases of meningioma were observed in the 20 years, and surgical treatment of intracranial meningioma was performed in 120 cases. Thirty-eight (9.6%) cases of cyst associated meningiomas were analyzed. Nauta type I was the most common type of cyst (39.5%) and the most frequent histopathological subtype was meningothelial type (36.8%).

Conclusion

Statistically there were no significant associations between meningioma histopathological type and associated cysts; however, the rate of World Health Organization grade II was higher in cyst associated meningiomas than in unrelated meningiomas. This correlation was weak, in accordance with the meningioma grade.

Joint Capsule-Like Intracranial Osteochondroma Mimicking Cystic Meningioma

This report provides the first representative images of an intracranial osteochondroma with a cystic component mimicking cystic meningioma. A 40-year-old male presented at our outpatient clinic with decreased sensation in his right upper extremity. Preoperative computed tomography showed a tumor with a cystic meningioma-like appearance and prominent calcifications. On magnetic resonance imaging, calcification of the lesion was suggested by the T2-weighted image; weak enhancement was seen on the T1-weighted image. Following surgical removal of the tumor, the pathologic examination showed findings consistent with osteochondroma. Cystic meningioma is a rare tumor with a cystic component. Intracranial osteochondroma is also a rare, benign tumor that can mimic meningioma when presenting in the dural convexity. Our report describes the joint capsule-like appearance of a convex cystic osteochondroma including a calcified cap, bonelike structure, and fluid-containing intracapsular space. The tumor was evaluated by imaging and pathologic studies.