Intraparenchymal Meningioma: Clinical, Radiologic, and Histologic Review

Imaging features of pediatric meningiomas: emphasis on unusual locations

PURPOSE

This article aims to analyze pediatric meningioma's imaging characteristics, especially those in unusual locations.

METHODS

Pediatric patients with pathologically confirmed meningiomas at our hospital from January 2010 to January 2024 were enrolled. Meningiomas located in the cerebral convexity, parasagittal falcine region, anterior skull base, middle skull base, sphenoid ridge, cerebellopontine angle (CPA), olfactory groove, or juxtasella were considered in usual locations. Meningiomas found in other areas were considered in unusual locations. Clinical information, pathology results, and imaging features of pediatric meningiomas in usual and usual locations were analyzed and compared.

RESULTS

A total of 18 patients (19 meningiomas) were enrolled, including 14 males and 4 females, with an average age of 14 years (ranging from 6 to 18 years). A total of 12 (63.2%) meningiomas were in the unusual location, including four (33.3%) were intraparenchymal, four (33.3%) were intraventricular, two (16.7%) were intraosseous, one (8.3%) case was in the paranasal sinus, and one (8.3%) was intraspinal. The meningiomas in unusual locations usually lacked the meningeal tail sign, and the misdiagnosis rate on preoperative imaging was significantly higher than that of meningiomas in usual locations.

CONCLUSION

Pediatric meningiomas are prone to occur in unusual locations. When they occur in usual locations, they often lack typical radiographic features of meningiomas, leading to potential misdiagnosis before surgery. Recognition of the imaging characteristics of meningiomas in unusual locations in children may facilitate accurate preoperative imaging diagnosis.

Intraparenchymal atypical meningioma in the posterior fossa: a case report and literature review

Intraparenchymal meningiomas without dural attachments are extremely rare. A 32-year-old female adult was admitted to our hospital, complaining of occasional dizziness. The patient had no neurological deficits. MRI demonstrated a lesion with mild edema located in the left cerebellar parenchyma. CT revealed calcification within the mass. Gross total resection was achieved. The histopathological examination indicated that the lesion was an atypical meningioma (WHO-II). We herein report an extremely rare case of an intraparenchymal meningioma located in the left cerebellar hemisphere. The significance of the differential diagnosis of lesions in the cerebellum should be emphasized.

A rare case of intra-parenchymal meningioma in a female patient who presented with seizures: A case report

Key Clinical Message

Meningiomas are slow-growing tumors that develop from the arachnoid cap cells' meningothelial cells. Males are more likely to develop intra-parenchymal meningiomas, which also manifest earlier than ordinary meningiomas and are uncommon.

Abstract

Meningiomas are slow-growing neoplasms which arise from the meningothelial cells of the arachnoid cap cells. Unlike other meningiomas, intra-parenchymal meningiomas do not originate from dura. Intra-parenchymal meningiomas are more common in males and develop earlier than regular meningiomas. Because of the rare occurrence the intra-parenchymal meningiomas, they are commonly misdiagnosed.

Perifocal Edema in Patients with Meningioma is Associated with Impaired Whole-Brain Connectivity as Detected by Resting-State fMRI

BACKGROUND AND PURPOSE

Meningiomas are intracranial tumors that usually carry a benign prognosis. Some meningiomas cause perifocal edema. Resting-state fMRI can be used to assess whole-brain functional connectivity, which can serve as a marker for disease severity. Here, we investigated whether the presence of perifocal edema in preoperative patients with meningiomas leads to impaired functional connectivity and if these changes are associated with cognitive function.

MATERIALS AND METHODS

Patients with suspected meningiomas were prospectively included, and resting-state fMRI scans were obtained. Impairment of functional connectivity was quantified on a whole-brain level using our recently published resting-state fMRI-based marker, called the dysconnectivity index. Using uni- and multivariate regression models, we investigated the association of the dysconnectivity index with edema and tumor volume as well as cognitive test scores.

RESULTS

Twenty-nine patients were included. In a multivariate regression analysis, there was a highly significant association of dysconnectivity index values and edema volume in the total sample and in a subsample of 14 patients with edema, when accounting for potential confounders like age and temporal SNR. There was no statistically significant association with tumor volume. Better neurocognitive performance was strongly associated with lower dysconnectivity index values.

CONCLUSIONS

Resting-state fMRI showed a significant association between impaired functional connectivity and perifocal edema, but not tumor volume, in patients with meningiomas. We demonstrated that better neurocognitive function was associated with less impairment of functional connectivity. This result shows that our resting-state fMRI marker indicates a detrimental influence of peritumoral brain edema on global functional connectivity in patients with meningiomas.

Intraparenchymal meningioma in the parieto-occipital region: A case report of a diagnostically challenging tumor

Background

Intraparenchymal meningioma is a rare entity of one of the most common brain tumors. It is challenging to diagnose preoperatively due to the vague clinical presentation and absence of stereotypical radiological features. These atypical features might mislead the differential to favor high-grade gliomas or brain metastasis.

Case Description

We describe a case of a 46-year-old male who presented with vertigo, right-sided sensorineural hearing loss, and bilateral blurred vision. Contrast-enhanced magnetic resonance imaging of the brain revealed a large parieto-occipital contrast-enhanced mass with a multi-loculated cystic component and diffusion restriction but without dural attachment. A gross total reaction was achieved, and the histopathological results yielded a World Health Organization Grade I meningioma diagnosis. The patient exhibited no signs of recurrence after 2 years of follow-up.

Conclusion

Intraparenchymal meningiomas are difficult to identify without histopathological assessment. We emphasize the importance of considering this diagnosis when outlining an initial differential as it may direct management planning. Total surgical resection is the best treatment modality for such cases; however, radiotherapy is a valuable option. The prognosis of intraparenchymal meningiomas is generally favorable.

Interhemispheric Pediatric Meningioma, YAP1 Fusion-Positive

Meningiomas are uncommon in children and usually arise in the context of tumor-predisposing syndromes. Recently, YAP1-fusions have been identified for the first time as potential NF2-independent oncogenic drivers in the development of meningiomas in pediatric patients. We report a case of a YAP1-fusion-positive atypical meningioma in a young child and compare it with the previous ones reported. Extending the clinico-pathological features of YAP1-fused meningiomas, we suggest additional clues for diagnosis and emphasize the urgent need for an integrated multilayered diagnostic approach, combining data from histological and molecular analyses, neuroradiology, and clinical findings.

Benign Meningioma With Rare Radiological and Behavioral Features

BACKGROUND

Meningiomas are usually dura-based primary nonmalignant neoplasms of the central nervous system. It is extremely rare that a meningioma is located at the convexity of the brain, but shows no dura attachment and causes osteolysis of the skull.

CASE PRESENTATION

A 57-year-old woman presented with an incidentally discovered scalp lump on the head. Neurological deficits were not found. Radiological examination revealed a localized osteolytic lesion in the right parietal bone, which was initially diagnosed as a bone tumor and was surgically resected. At surgery, a tumor mass was found located at the brain convexity without dura attachment. It was tightly attached to the brain parenchyma and had no distinct boundary from the brain. The mass was rather small, but resulted in significant osteolysis of the skull and destruction of the dura. Simpson grade I resection of the tumor was performed. Histological and immunohistochemical results indicated a meningothelial meningioma.

CONCLUSIONS

Both preoperative and intraoperative diagnoses are difficult for this case. Knowledge of this case is crucial for clinicians to be aware of this entity because it can be easily confused with bone tumors. Further research on the relationship between meningioma and bone metabolism is required to investigate the mechanism of osteolysis.

Intraparenchymal Meningioma

Meningiomas have been described as the most frequent extra-axial tumor in the brain. Most are benign and correspond to World Health Organization (WHO) grade I; however, there are some reports of cases that shows atypical locations, like subcortical intra-axial meningiomas. This represents a challenge in radiological diagnosis because it could be taken as a metastasis tumor or vascular malformations. The authors bring a case report of a previously healthy patient who presents a traumatic brain injury with no traumatic lesions. A computed tomography (CT) evidenced a left frontal rounded subcortical lesion surrounded by large vasogenic edema. The first diagnostic impression was a metastasis tumor. During surgery, a total resection was completed, and the appearance of the tumor was meningioma. This was later confirmed by histological analysis. The literature was reviewed in order to determine the importance of including intraparenchymal meningiomas in the differential diagnosis of intracranial lesions.

Primary Intraparenchymal Meningiomas: A Case Report and a Systematic Review

BACKGROUND

Primary intraparenchymal meningiomas are exceedingly rare and often challenging to diagnose, given their misleading radiologic features. It is hypothesized that they arise from the cap cells of the pia mater that enter the brain via penetrating blood vessels during brain development. We systematically reviewed and analyzed previously reported features of primary intraparenchymal meningiomas in terms of radiography, presenting symptoms, and histopathology.

METHODS

A literature search of the Web of Science and PubMed databases and crossed references was performed in March 2021, per PRISMA guidelines, with no restrictions regarding publication date. Data regarding demographic features, clinical, radiographic, and histopathologic characteristics were extracted.

RESULTS

A total of 52 patients (including the reported case) were included in this review. The mean age was 21.1 years (range, 0.3-66 years) with a male/female ratio of 1.9:1. The most common localizations of intraparenchymal meningiomas were in the frontal (30.8%) and temporal (21.2%) lobes. Cyst formation was more readily observed and was noted in 51.4% of patients. Histopathology showed a higher incidence of World Health Organization grade II (14/52, 26.9%) and World Health Organization grade III (7/52, 13.5%) of primary intraparenchymal meningiomas.

CONCLUSIONS

We present a comprehensive analysis of every reported primary intraparenchymal meningioma. Because of their rarity and capacity to mimic other more common intra-axial tumors, they represent a diagnostic challenge. This systematic review highlights the importance of paying attention to atypical intra-axial lesions, with a particular reflection on the discrepancy between clinical characteristics and imaging features.

Giant Intraparenchymal Meningioma in a Female Child: Case Report and Literature Review

BACKGROUND

Intraparenchymal meningiomas without dural attachment are extremely rare, especially in female children. To our knowledge, fibrous intraparenchymal meningioma located in the temporal lobe has never been reported in female children. The significance in the differential diagnosis of lesions in the temporal lobe should be emphasized.

CASE PRESENTATION

A 12-year-old girl was admitted to our hospital, complaining of recurrent generalized seizures for 2 months. Magnetic resonance imaging demonstrated a solid lesion located in the temporal lobe. The lesion underwent gross total resection. Histopathological examination indicated that the lesion was a fibrous meningioma. Postoperative rehabilitation was uneventful.

CONCLUSION

This case report presents an extremely unusual intraparenchymal fibrous meningioma of the temporal lobe with peritumoral edema and reviewed 21 intraparenchymal meningioma cases in children and to discuss the clinical presentation and treatment, differential diagnosis, and radiological features.

Individual-patient prediction of meningioma malignancy and survival using the Surveillance, Epidemiology, and End Results database

Meningiomas are known to have relatively lower aggressiveness and better outcomes than other central nervous system (CNS) tumors. However, there is considerable overlap between clinical and radiological features characterizing benign, atypical, and malignant tumors. In this study, we developed methods and a practical app designed to assist with the diagnosis and prognosis of meningiomas. Statistical learning models were trained and validated on 62,844 patients from the Surveillance, Epidemiology, and End Results database. We used balanced logistic regression-random forest ensemble classifiers and proportional hazards models to learn multivariate patterns of association between malignancy, survival, and a series of basic clinical variables-such as tumor size, location, and surgical procedure. We demonstrate that our models are capable of predicting meaningful individual-specific clinical outcome variables and show good generalizability across 16 SEER registries. A free smartphone and web application is provided for readers to access and test the predictive models (www.meningioma.app). Future model improvements and prospective replication will be necessary to demonstrate true clinical utility. Rather than being used in isolation, we expect that the proposed models will be integrated into larger and more comprehensive models that integrate imaging and molecular biomarkers. Whether for meningiomas or other tumors of the CNS, the power of these methods to make individual-patient predictions could lead to improved diagnosis, patient counseling, and outcomes.

Sylvian Fissure Meningioma in Childhood: Report of 3 Cases and Review of the Literature

OBJECTIVE

Sylvian fissure-based meningioma is a rare occurrence during childhood. We report a small series including 3 such cases, all attached to the arachnoid leaflets of the Sylvian fissure. We present a review of the literature and discuss the impact of possibly effective clinical, imaging, and surgical variables on the outcome.

METHODS

In a retrospective chart review of children with intracranial meningioma, we encountered 3 cases with Sylvian fissure meningioma operated within the past 32 years.

RESULTS

Two girls, 5 and 7 years old, and 1 boy, 7 years of age, presented with epilepsy, headache, diplopia, and hemiparesis. The duration of illness was 3, 4, and 2 months, respectively. All three tumors were attached to the arachnoid layer of the adjacent Sylvian fissure, and they were not dural based. Gross total resection could be achieved, and no recurrences were encountered after 13, 7, and 2 years.

CONCLUSION

We report 3 very rare cases of Sylvian arachnoid-based meningiomas. To our knowledge, this is the study with the longest follow-up period (mean 7.3 years, median 7 years). Even though the overall prognosis of pediatric meningiomas may be worse than that of adult illness, we would like to emphasize that the "rare location" of the Sylvian fissure was not an important factor contributing to the outcome in our children.

Intraparenchymal supratentorial papillary meningioma: a case report

Although intraparenchymal meningiomas have rarely been reported in the literature, the papillary type has been reported only as infratentorial. Here we report the case of a 21-year-old female patient with intraparenchymal lesion. To our knowledge, this case describes the first report of a patient with a supratentorial intraparenchymal papillary meningioma.

Sporadic pediatric meningiomas: a neuroradiological and neuropathological study of 15 cases

OBJECTIVE Sporadic meningiomas have been classified in many different ways. Radiographically, these lesions can be described as occurring in either typical or atypical locations. The purpose of this study was to determine if there are any histopathological differences between sporadic meningiomas that arise in these varying locations in children. METHODS The neuroimaging, histopathological findings, and clinical records in patients with sporadic pediatric meningiomas not associated with neurofibromatosis Type 2 or prior radiation therapy were retrospectively reviewed. Tumors were classified by radiological findings as either typical or atypical, and they were categorized histopathologically by using the latest WHO nomenclature and grading criteria. RESULTS Fifteen sporadic meningiomas in pediatric patients were biopsied or resected at the authors' institution between 1989 and 2013. Five (33%) were typical in radiographic appearance and/or location and 10 (67%) were atypical. Four (80%) typical meningiomas were WHO Grade I tumors. Most (60%) of the atypical meningiomas were WHO Grade II or III. CONCLUSIONS This study is the largest series of sporadic pediatric meningiomas in atypical locations to date. Although sporadic meningiomas are relatively infrequent in children, those with atypical imaging, specifically those with apparently intraparenchymal and intraosseous locations, may be more common than previously recognized. In this study, pediatric sporadic meningiomas arising in atypical locations, in particular intraparenchymal meningiomas, may be of higher histopathological grade. The authors' findings should alert clinicians to the potential for more aggressive clinical behavior in these tumors.