Primary Intracranial Ewing Sarcoma With EWSR1-FLI1 Gene Translocation Mimicking a Meningioma and a Multidisciplinary Therapeutic Approach: A Case Report and Systematic Review of Literatures

Ewing sarcoma and peripheral primitive neuroectodermal tumor (ES/pPNET) is an undifferentiated malignant tumor that is most prevalent in children and young adults and often radiologically mimics a meningioma. A 38-year-old female patient visited our hospital with complaints of right-sided tinnitus, right hemiparesis, and imbalance. She underwent preoperative imaging and was subsequently diagnosed as having a meningioma on the petrous ridge. After partial resection, EWSR1-FLI1 gene fusion was confirmed, and she was diagnosed with ES/pPNET. The tumor was successfully treated using a multidisciplinary approach of adjuvant chemo- and radiotherapy. This case is noteworthy because it is an extremely rare case of an intracranial ES/pPNET, and it is worth sharing our clinical experience that the tumor was successfully treated through a multidisciplinary therapeutic approach even though complete resection was not achieved.

How I do it: intradural anterior petrosectomy

BACKGROUND

The anterior transpetrosal approach (ATPA) is a cranial base approach for addressing upper petroclival or lateral pontine lesions. It is fundamentally an epidural procedure involving the drilling of the petrous apex. However, this approach has significant procedure-related morbidity, and the surgeon must perform a complete petrosectomy, as the intradural structures are not in view during the drilling. For selected cases, a rationale exists for choosing a tailor-made intradural anterior petrosectomy (IAP).

METHOD

This article describes the relevant surgical anatomy and the different surgical steps of the IAP.

CONCLUSION

IAP represents a feasible alternative to the standard ATPA with the advantage of minimizing the extent of petrous bone removal to the individual need.

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.

A potential role of mechano-gated potassium channels in meningioma-related seizures

Every third patient with intracranial meningioma develops seizures of poorly understood etiology. Tumor and peritumoral edema may exert mechanical pressure on the cortex that may affect mechano-gated potassium channels - KCNK2 and KCNK4. These channels regulate neuron excitability and have been related to seizures in some other conditions. The objective of the present study was to explore a potential relation between the levels of these proteins in tumor tissue and adjacent cortex and seizures development. The study included 19 meningioma patients that presented one or more preoperative seizures and 24 patients with no seizures. Tissue samples were collected in the course of surgical removal of the meningioma. Postoperative seizure freedom was achieved in 11 out of 19 patients. The relative level of KCNK2 in the cortical tissue was lower in patients with preoperative seizures. On the other hand, cortical tissue level of KCNK4 was higher in patients that became seizure-free after the surgery. In addition, relative levels of KCNK4 in the cortical and tumor tissue appear to be lowered by the treatment with anti-seizure medication levetiracetam. These results imply that KCNK2 and KCNK4 may be involved in the development of meningioma-related seizures and may represent promising therapeutic targets.

Automated segmentation of meningioma from contrast-enhanced T1-weighted MRI images in a case series using a marker-controlled watershed segmentation and fuzzy C-means clustering machine learning algorithm

INTRODUCTION AND IMPORTANCE

Accurate segmentation of meningiomas from contrast-enhanced T1-weighted (CE T1-w) magnetic resonance imaging (MRI) is crucial for diagnosis and treatment planning. Manual segmentation is time-consuming and prone to variability. To evaluate an automated segmentation approach for meningiomas using marker-controlled watershed segmentation (MCWS) and fuzzy c-means (FCM) algorithms.

CASE PRESENTATION AND METHODS

CE T1-w MRI of 3 female patients (aged 59, 44, 67 years) with right frontal meningiomas were analyzed. Images were converted to grayscale and preprocessed with Otsu's thresholding and FCM clustering. MCWS segmentation was performed. Segmentation accuracy was assessed by comparing automated segmentations to manual delineations.

CLINICAL DISCUSSION

The approach successfully segmented meningiomas in all cases. Mean sensitivity was 0.8822, indicating accurate identification of tumors. Mean Dice similarity coefficient between Otsu's and FCM1 was 0.6599, suggesting good overlap between segmentation methods.

CONCLUSION

The MCWS and FCM approach enables accurate automated segmentation of meningiomas from CE T1-w MRI. With further validation on larger datasets, this could provide an efficient tool to assist in delineating meningioma boundaries for clinical management.

Long-term antiseizure medication use in patients after meningioma resection: identifying predictors for successful weaning and failures

OBJECTIVE

To define risk factors for meningioma-related seizures and predictors of successful weaning of antiseizure medications following meningioma resection.

METHODS

This is a retrospective study of 95 patients who underwent meningioma resection at a single institution. Primary outcome analyzed was ability to achieve seizure freedom without the use of anti-seizure medication at 6-months, 1-year, and last known follow up. Secondary outcome was postoperative seizure freedom.

RESULTS

Preoperative seizures (OR: 11.63, 95% CI [3.64, 37.17], p < 0.0001), non-skull base tumor location (OR: 3.01, 95% CI [1.29, 7.02], p = 0.0128), and modified STAMPE score of 3-5 (OR: 5.42, 95% CI [2.18, 13.52], p = 0.0003) were associated with greater likelihood of remaining on antiseizure medication at 6-month follow up. Preoperative seizures (OR: 4.93, 95% CI: [2.00, 12.16 ], p = 0.0008), intratumoral calcifications (OR: 4.19, 95% CI: [1.61, 14.46], p = 0.0055), modified STAMPE score of 3-5 (OR: 5.42, CI [2.18, 13.52], p = 0.0003), and Ki67 greater than 7% (OR: 5.68, CI [1.61, 20.10], p = 0.0060) were significant risk factors for inability to discontinue ASMs by last follow up. Preoperative seizures (OR: 4.33, 95% CI [1.59, 11.85], p = 0.0050) and modified STAMPE score of 3-5 (OR: 6.09, 95% CI [2.16, 17.20], p = 0.0007) were significant risk factors for postoperative seizures.

CONCLUSIONS

Preoperative seizures, modified STAMPE2 score of 3-5, non-skull base tumor location, intratumoral calcifications, and Ki67 > 7% were significant risk factors for inability to achieve seizure freedom without ASMs. In addition, the modified STAMPE2 score successfully predicted increased seizure risk following meningioma resection for patients with a score of 3 or higher.

Applying Shear Wave and Magnetic Resonance Elastography to Grade Brain Tumors: Systematic Review and Meta-Analysis

BACKGROUND

Reports find that magnetic resonance elastography (MRE) and shear wave elastography (SWE) can classify intracranial tumors according to stiffness. However, systematic syntheses of these articles are lacking. In this report, a systematic review and meta-analysis was performed to evaluate whether SWE and MRE can predict meningioma and glioma grades.

METHODS

PubMed and Scopus were searched between February 10, 2022. and March 2, 2022. using manual search criteria. Eight out of 106 non-duplicate records were included, encompassing 84 patients with low-grade tumors (age 42 ± 13 years, 71% female) and 92 patients with high-grade tumors (age 50 ± 13 years, 42% female). Standardized mean difference in stiffness between high-grade and low-grade tumors were measured using a forest plot. The I2, χ2, and t tests were performed, and bubble plots were constructed to measure heterogeneity. An adapted QUADAS-2 scale evaluated study quality. Additionally, a funnel plot was constructed, and an Egger's intercept test determined study bias.

RESULTS

Low-grade tumors were stiffer than high-grade tumors (Cohen's D = -1.25; 95% CI -1.88, -0.62). Moderate heterogeneity was observed (I2 = 67%; P = 0.006) but controlling for publication year (I2 = 0.2%) and age (I2 = 0.0%-17%) reduced heterogeneity. Included studies revealed unclear or high bias for the reference standard and flow and timing (>50%).

CONCLUSIONS

Elastography techniques have potential to grade tumors intraoperatively and postoperatively. More studies are needed to evaluate the clinical utility of these technologies.

Brain meningioma incidentally detected on a bone scan: A Case report

Incidental meningioma is defined as a mass diagnosed radiologically on MRI and CT scans without histopathological confirmation. In occasional cases, meningiomas can be diagnosed incidentally by bone scintigraphy. This article presents an interesting case where a 44-year-old lady with known breast cancer was found to have a brain meningioma, incidentally, detected on a bone scan, which was initially suspected to be metastatic brain changes. The follow-up MRI and histopathological studies confirmed the diagnosis of meningioma.

Metastatic meningioma: a case series and systematic review

BACKGROUND

Meningiomas are the most common primary intracranial tumor. While the majority of meningiomas are benign, rarely they can metastasize extracranially. There is a need for a more comprehensive review of these patients to improve our understanding of this rare phenomenon and its prevalence globally. Here we describe our institution's experience of patients presenting with metastatic meningiomas. We further perform a systematic review of the existing literature to explore common features of this rare manifestation of meningioma and review the efficacy of current treatments.

METHODS

We performed a retrospective clinical review of all adult patients with metastatic meningioma managed at our institution over the past 20 years, identifying 6 patients. We then performed a systematic review of cases of metastatic meningioma in the literature ranging from the years 1886 to 2022. A descriptive analysis was then conducted on the available data from 1979 onward, focusing on the grade and location of the primary tumor as well as the latency period to, and location of, the metastasis.

RESULTS

In total, we analyzed 155 cases. Fifty-four percent of patients initially presented with a primary meningioma located in the convexity. The most common site of metastasis was the lung. Risk factors associated with a shorter time to metastasis were male sex and a high initial grade of the tumor. Regarding treatment, the addition of chemotherapy was the most common adjunct to the standard management of surgery and radiotherapy. Despite an exhaustive review we were unable to identify effective treatments. The majority of published cases came from centers situated in high-income countries (84%) while only 16% came from lower- and middle-income countries.

CONCLUSIONS

Metastatic meningiomas pose a pertinent, and likely underestimated, clinical challenge within modern neurosurgery. To optimize management, timely identification of these patients is important. More research is needed to explore the mechanisms underlying these tumors to better guide the development of effective screening and management protocols. However, screening of each meningioma patient is not feasible, and at the heart of this challenge is the inability to control the primary disease. Ultimately, a consensus is needed as to how to correctly screen for and manage these patients; genomic and epigenomic approaches could hold the answer to finding druggable targets.

Extradural disconnection of the cavernous sinus with preservation of the internal carotid artery: indication and technique

BACKGROUND

Extradural disconnection of the cavernous sinus (CS) with preservation of the internal carotid artery (ICA) is indicated for aggressive and recurrent tumors, in patients presenting loss of oculomotor function and non-functional circle of Willis.

METHOD

Extradural resection of the anterior clinoid process disconnects the CS anteriorly. The ICA is dissected in the foramen lacerum via extradural subtemporal approach. The intracavernous tumor is split and removed following the ICA. Bleeding control of the inferior and superior petrosal and intercavernous sinuses completes posterior CS disconnection.

CONCLUSION

This technique can be proposed for recurrent CS tumors and need of ICA preservation.

Cerebellopontine angle meningioma originating from choroid plexus of the foramen of Luschka: An extremely rare entity and overlook of literature

INTRODUCTION AND IMPORTANCE

Meningiomas without dural attachments are quite a novelty, with such meningiomas in the posterior fossa being even more far and few between. The authors describe an extremely rare cerebellopontine angle (CPA) meningioma lacking a dural attachment arising from the choroid plexus of the foramen of Luschka (CPFOL).

CASE PRESENTATION

A 35-year-old male presented to our center complaining of a generalized and progressive headache for 10 months. A 3 cm × 4 cm well-defined lesion in the left CPA, hypointense in T1 and hyperintense in T2-weighted magnetic resonance imaging (MRI), was noted with no evident dural base or dural attachment. CPFOL was appreciated right at the point where the tumoral base was detected, which implied that the tumor originated from CPFOL. A gross total resection (GTR) was achieved, with the postoperative period remaining uneventful. The histopathologic investigation confirmed a transitional meningioma World Health Organization (WHO) grade I with no atypical features.

CLINICAL DISCUSSION

Meningioma without dural attachment remains a rare phenomenon, with few available in English literature, and such pathology in the posterior fossa is even more unusual. Discriminating between CPFOL and another kind of CPA meningioma is mandatory when dealing with intracranial meningioma surgeries.

CONCLUSION

While managing a space-occupying lesion around CPA, although extremely rare, a meningioma originating from CPFOL is suggested to be included in the differentials with necessary imaging analysis and advised to be imperatively pursued before proceeding for surgical intervention.

Dural reconstruction following resection of ventral and lateral spinal cord meningiomas: Fenestrated Durotomy with Oversized Graft technique

BACKGROUND

Meningiomas, although benign, often require complete resection due to their tendency for recurrence. However, dural reconstruction poses significant challenges, especially in the case of ventral meningiomas. While some reports have highlighted the usefulness of dural reconstruction using an artificial dura mater, no studies have yet confirmed dural canal enlargement through MRI post-surgically. This study aimed to assess the effectiveness of the Fenestrated Durotomy with Oversized Graft (FDOG) technique in cases of meningiomas and other intradural extramedullary tumors and evaluated dural canal dilation through MRI after using an artificial dura mater.

METHODS

This retrospective case series included 8 patients who underwent combined resection of intradural extramedullary tumors and dural repair using the FDOG technique. An artificial dura mater larger than that resected was inserted into the dural defect resulting from complete tumor resection on the ventral or lateral side of the spinal cord. The new dura mater was secured with a single dorsal suture. The dural incision was closed using watertight sutures following standard procedure. Measurement of the extent of dural canal enlargement was achieved via pre- and postoperative MRI scans.

RESULTS

None of the patients required additional treatments or lumbar drainage. All achieved independent ambulation without complications, and imaging tests indicated satisfactory dural expansion without signs of cerebrospinal fluid leakage.

CONCLUSIONS

The proposed method for dural repair in cases involving large dural defects on the ventral or lateral side of the spinal cord was shown to be a straightforward and effective approach with minimal postoperative complications.

Outcome and quality of life after intracranial meningioma surgery in cats

OBJECTIVES

The present study aimed to evaluate the postoperative quality of life (QOL) after surgery for the treatment of intracranial meningioma in cats.

METHODS

The study included 14 cases that underwent craniotomy from May 2009 to March 2021. Owners were contacted via telephone after a median time of 967 (range 227-4209) days after surgery and surveyed with a specially designed questionnaire that consisted of three domains, subdivided into different items. Physical behaviour, including general condition, food intake, mobility and overall impression, was evaluated from 0, reflecting the worst status, to 10, reflecting the best. The development of preoperative existing clinical signs, seizures and concurrent medication were evaluated individually for each patient. The time span necessary for the improvement of each item was recorded. Finally, satisfaction about the decision for surgery was ranked from 0 to 10.

RESULTS

Thirteen questionnaires were completed. Three cats were evaluated twice owing to revision surgery. Owners reported a statistically significant (P <0.001) improvement from immediately after the operation to 240 days after surgery. Preoperative clinical signs resolved in 95% of cases. All questioned owners would opt for surgery again.

CONCLUSIONS AND RELEVANCE

QOL after surgery for intracranial meningioma in cats seems encouraging regarding our study. Nevertheless, limitations, such as small sample size, recall bias, lack of a control group and validation of the questionnaire, need to be kept in mind when interpreting the results.

Primary large B-cell lymphoma involving the cerebellopontine angle mimic acoustic schwannoma: Role of MR Spectroscopy in differential diagnosis. A case report

Primary central nervous system (CNS) lymphoma is a very rare aggressive non-Hodgkin disease that originates in CNS (brain, leptomeninges, spinal cord, or eyes). It seems to have increased over the last two decades in both immunocompromised and immunocompetent patients. Primary large B-cell lymphoma involving the cerebellopontine angle (CPA) is extremely rare: only 15 cases of large B-cell lymphoma of the CPA have been reported worldwide; based on our knowledge, no cases studied with MR Spectroscopy. Primary large B-cell lymphoma of the CPA must be differentiated from other cerebellopontine angle diseases, such as acoustic neuroma and meningioma. An early and accurate diagnosis of this neoplasm is necessary for the best management because it is a radiosensitive and chemosensitive tumor. Herein, we report a rare case of B-cell lymphoma involving the left CPA in a 65-year-old man who presented with 3 months of hearing loss on the left, illustrated by MR and TC imaging, highlighting how the MR Spectroscopy, thanks to their greater specificity, is decisive in achieving the correct diagnosis of primary lymphoma and differentiating it from acoustic schwannoma or meningioma. Therefore, in the suspicion of a malignant heteroplastic lesion of the CPA, we suggest including Spectroscopy in the MR study protocol.

Frontal trans-sinusal approach: how I do it

BACKGROUND

Anterior skull base lesions could be reached by different approaches (subfrontal, pterional, interhemispheric, etc.). In selected cases, the frontal trans-sinusal approach is an effective alternative to conventional techniques.

METHODS

We present our technique to perform a frontal trans-sinusal approach in a patient affected by a large olfactory groove meningioma.

DISCUSSION-CONCLUSION

The frontal trans-sinusal approach allows to approach safely lesions of the median anterior cranial fossa. This approach provides lower brain retraction, easier access to olfactory grooves, and earlier tumor devascularization. However, it remains limited to patients with large-sized frontal sinuses and entails some postoperative risks such as mucocele or CSF leak.

Massive Hyperostotic Meningioma En Plaque Mimicking Fibrous Dysplasia

The authors report an extremely rare case of a massive hyperostotic meningioma en plaque, which had characteristics of unique bony growth. A 34-year-old man presented with a palpable solid mass in the left cranial region that had gradually grown in size with a broad base on the calvarium for 8 years. Radiologically, the area involved by the mass ranged from the sphenoid bone to the frontal, parietal, temporal, and occipital bones. Three-dimensional CT revealed multiple growing spiculate features on the inner and outer cranial surface. Even though the radiologic features resembled fibrous dysplasia, it was histologically found to be a type of meningioma.

Approaching Intradural Lesions of the Anterior Foramen Magnum and Craniocervical Junction: Anatomical Comparison of the Open Posterolateral and Anterior Extended Endonasal Endoscopic Approaches

BACKGROUND

Lesions of the foramen magnum (FM) and craniocervical junction area are traditionally managed surgically through anterior, anterolateral, and posterolateral skull-base approaches. This anatomical study aimed to compare the usefulness of a modified extended endoscopic approach, the so-called far-medial endonasal approach (FMEA), versus the traditional posterolateral far-lateral approach (FLA).

METHODS

Ten fixed silicon-injected heads specimens were used in the Skull Base ENT-Neurosurgery Laboratory of the University Hospital of Strasbourg, France. A total of 20 FLAs and 10 FMEAs were realized. A high-resolution computed tomography scan was performed for quantitative analysis of the different approaches. The analysis aimed to estimate the extent of surgical exposure and freedom of movement (maneuverability) through the operating channel using a polygonal surface model to obtain a morphometric estimation of the area of interest (surface and volume) on postdissection computed tomography scans using Slicer 3D software.

RESULTS

FMEA allows for a more direct route to the anterior FM, with wider brainstem exposure compared with the FLA and an excellent visualization of all anterior midline structures. The limitations of the FMEA include the deep and narrow surgical corridor and difficulty in reaching lesions located laterally over the jugular foramen and hypoglossal canal.

CONCLUSIONS

The FMEA and FLA are both effective surgical routes to reach FM and craniocervical junction lesions. Modern skull base surgeons should have a good command of both because they appear complementary. This anatomical study provides the tools for comprehensive preoperative evaluations and selection of the most appropriate surgical approach.

Combined retrosigmoid and middle fossa approach for a small, superiorly located petroclival meningioma: how I do it

BACKGROUND

Petroclival meningiomas pose significant surgical challenges because of their deep location and complex surrounding neurovasculature. The use of multiple surgical approaches can optimize safe tumor removal from multiple anatomic compartments.

METHOD

We describe a patient with a growing superior petroclival meningioma centered at the posterior clinoid with extension into Meckel's cave that was successfully removed with a combined retrosigmoid and subtemporal middle fossa approach. This strategy avoided the need for anterior petrous bone drilling and tentorial splitting.

CONCLUSION

A combined retrosigmoid and subtemporal middle fossa approach can provide safe access to tumors spanning the supra- and infratentorial compartments.

Bibliometric analysis of the top 100 cited articles on stereotactic radiosurgery of intracranial meningiomas

BACKGROUND

Sterotactic radiosurgery is becoming an integral modality in the management of intracranial meningiomas, both as the primary treatment or as adjuvant therapy. This study analyzes the scholarly impact of the top 100 cited articles on the stereotactic radiosurgical management of intracranial meningiomas.

METHODS

A ranked list of the 100 most-cited articles was generated using the Scopus database by searching the keywords 'intracranial meningioma' and 'stereotactic radiosurgery'. All articles were then evaluated on multiple criteria regarding both the publication of the articles (year of publication, journal, country of origin, and authors) as well as their methods and foci (type of study, location of studied meningiomas, and type of radiosurgical modality). Quantitaitve and qualitative analyses were then performed from the collected data.

RESULTS

The most frequently cited articles on stereotactic radiosurgical management of intracranial meningiomas were published between 1990 and 2016. The average citation-per-year across all papers in the list was 6.1. The most studied anatomic area of intracranial meningiomas was the skull base, with the cavernous sinus being the most well-studied specific site. The most utilized stereotactic radiosurgical modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Twenty-six percent of the articles were published in the journal Neurosurgery; Lunsford, Kondziolka, Flickinger, Sheehan, and Pollock were respectively the most frequent listed authors among this list. The most active academic institute publishing on this topic was the University of Pittsburgh Medical Center.

CONCLUSION

Stereotactic radiosurgery is an integral modality in the management of intracranial meningiomas. This bibliometric analysis sheds the light on the ways in which intracranial meningiomas have been studied in the past two decades in order to identify trends among neurosurgeons and radiation oncologists and to reveal areas of rising and declining focus.

A large-scale targeted proteomics of serum and tissue shows the utility of classifying high grade and low grade meningioma tumors

BACKGROUND

Meningiomas are the most prevalent primary brain tumors. Due to their increasing burden on healthcare, meningiomas have become a pivot of translational research globally. Despite many studies in the field of discovery proteomics, the identification of grade-specific markers for meningioma is still a paradox and requires thorough investigation. The potential of the reported markers in different studies needs further verification in large and independent sample cohorts to identify the best set of markers with a better clinical perspective.

METHODS

A total of 53 fresh frozen tumor tissue and 51 serum samples were acquired from meningioma patients respectively along with healthy controls, to validate the prospect of reported differentially expressed proteins and claimed markers of Meningioma mined from numerous manuscripts and knowledgebases. A small subset of Glioma/Glioblastoma samples were also included to investigate inter-tumor segregation. Furthermore, a simple Machine Learning (ML) based analysis was performed to evaluate the classification accuracy of the list of proteins.

RESULTS

A list of 15 proteins from tissue and 12 proteins from serum were found to be the best segregator using a feature selection-based machine learning strategy with an accuracy of around 80% in predicting low grade (WHO grade I) and high grade (WHO grade II and WHO grade III) meningiomas. In addition, the discriminant analysis could also unveil the complexity of meningioma grading from a segregation pattern, which leads to the understanding of transition phases between the grades.

CONCLUSIONS

The identified list of validated markers could play an instrumental role in the classification of meningioma as well as provide novel clinical perspectives in regard to prognosis and therapeutic targets.

MRI-based machine learning models predict the malignant biological behavior of meningioma

BACKGROUND

The WHO grade and Ki-67 index are independent indices used to evaluate the malignant biological behavior of meningioma. This study aims to develop MRI-based machine learning models to predict the malignant biological behavior of meningioma from the perspective of the WHO grade, Ki-67 index, and their combination.

METHODS

This multicenter, retrospective study included 313 meningioma patients, of which 70 were classified as high-grade (WHO II/III) and 243 as low-grade (WHO I). The Ki-67 expression was classified into low-expression (n = 216) and high-expression (n = 97) groups with a threshold of 5%. Among them, there were 128 patients with malignant biological behavior whose WHO grade or Ki-67 index increased either or both. Data from Center A and B are were utilized for model development, while data from Center C and D were used for external validation. Radiomic features were extracted from the maximum cross-sectional area (2D) region of Interest (ROI) and the whole tumor volume (3D) ROI using different paraments from the T1, T2-weighted, and T1 contrast-enhanced sequences (T1CE), followed by five independent feature selections and eight classifiers. 240 prediction models were constructed to predict the WHO grade, Ki-67 index and their combination respectively. Models were evaluated by cross-validation in training set (n = 224). Suitable models were chosen by comparing the cross-validation (CV) area under the curves (AUC) and their relative standard deviations (RSD). Clinical and radiological features were collected and analyzed; meaningful features were combined with radiomic features to establish the clinical-radiological-radiomic (CRR) models. The receiver operating characteristic (ROC) analysis was used to evaluate those models in validation set. Radiomic models and CRR models were compared by Delong test.

RESULTS

1218 and 1781 radiomic features were extracted from 2D ROI and 3D ROI of each sequence. The selected grade, Ki-67 index and their combination radiomic models were T1CE-2D-LASSO-LR, T1CE-3D-LASSO-NB, and T1CE-2D-LASSO-LR, with cross-validated AUCs on the training set were 0.857, 0.798, and 0.888, the RSDs were 0.06, 0.09, and 0.05, the validation set AUCs were 0.829, 0.752, and 0.904, respectively. Heterogeneous enhancement was found to be associated with high grade and Ki-67 status, while surrounding invasion was associated with the high grade status, peritumoral edema and cerebrospinal fluid space surrounding tumor were correlated with the high Ki-67 status. The Delong test showed that these significant radiological features did not significantly improve the predictive performance. The AUCs for CRR models predicting grade, Ki-67 index, and their combination in the validation set were 0.821, 0.753, and 0.906, respectively.

CONCLUSIONS

This study demonstrated that MRI-based machine learning models could effectively predict the grade, Ki-67 index of meningioma. Models considering these two indices might be valuable for improving the predictive sensitivity and comprehensiveness of prediction of malignant biological behavior of meningioma.

Meningiomas in patients with neurofibromatosis type 2 predominantly comprise 'immunogenic subtype' tumours characterised by macrophage infiltration

Although recent molecular analyses revealed that sporadic meningiomas have various genetic, epigenetic, and transcriptomic profiles, meningioma in patients with neurofibromatosis type 2 (NF2) have not been fully elucidated. This study investigated meningiomas' clinical, histological, and molecular characteristics in NF2 patients. A long-term retrospective follow-up (13.5 ± 5.5 years) study involving total 159 meningiomas in 37 patients with NF2 was performed. Their characteristics were assessed using immunohistochemistry (IHC), bulk-RNA sequencing, and copy number analysis. All variables of meningiomas in patients with NF2 were compared with those in 189 sporadic NF2-altered meningiomas in 189 patients. Most meningiomas in NF2 patients were stable, and the mean annual growth rate was 1.0 ± 1.8 cm3/year. Twenty-eight meningiomas (17.6%) in 25 patients (43.1%) were resected during the follow-up period. WHO grade I meningiomas in patients with NF2 were more frequent than in sporadic NF2-altered meningiomas (92.9% vs. 80.9%). Transcriptomic analysis for patients with NF2/sporadic NF2-altered WHO grade I meningiomas (n = 14 vs. 15, respectively) showed that tumours in NF2 patients still had a higher immune response and immune cell infiltration than sporadic NF2-altered meningiomas. Furthermore, RNA-seq/IHC-derived immunophenotyping corroborated this enhanced immune response by identifying myeloid cell infiltration, particularly in macrophages. Clinical, histological, and transcriptomic analyses of meningiomas in patients with NF2 demonstrated that meningiomas in NF2 patients showed less aggressive behaviour than sporadic NF2-altered meningiomas and elicited a marked immune response by identifying myeloid cell infiltration, particularly of macrophages.

Role of Mediterranean diet in the development and recurrence of meningiomas: a narrative review

Several studies through the years have proven how an unhealthy nutrition, physical inactivity, sedentary lifestyle, obesity, and smoking represent relevant risk factors in cancer genesis. This study aims to provide an overview about the relationship between meningiomas and food assumption in the Mediterranean diet and whether it can be useful in meningioma prevention or it, somehow, can prevent their recurrence. The authors performed a wide literature search in PubMed and Scopus databases investigating the presence of a correlation between Mediterranean diet and meningiomas. The following MeSH and free text terms were used: "Meningiomas" AND "Diet" and "Brain tumors" AND "diet." Databases' search yielded a total of 749 articles. After duplicate removal, an abstract screening according to the eligibility criteria has been performed and 40 articles were selected. Thirty-one articles were excluded because they do not meet the inclusion criteria. Finally, a total of 9 articles were included in this review. It is widely established the key and protective role that a healthy lifestyle and a balanced diet can have against tumorigenesis. Nevertheless, studies focusing exclusively on the Mediterranean diet are still lacking. Thus, multicentric and/or prospective, randomized studies are mandatory to better assess and determine the impact of food assumptions in meningioma involvement.

Differential diagnosis of atypical and anaplastic meningiomas based on conventional MRI features and ADC histogram parameters using a logistic regression model nomogram

The purpose of the study was to determine the value of a logistic regression model nomogram based on conventional magnetic resonance imaging (MRI) features and apparent diffusion coefficient (ADC) histogram parameters in differentiating atypical meningioma (AtM) from anaplastic meningioma (AnM). Clinical and imaging data of 34 AtM and 21 AnM diagnosed by histopathology were retrospectively analyzed. The whole tumor delineation along the tumor edge on ADC images and ADC histogram parameters were automatically generated and comparisons between the two groups using the independent samples t test or Mann-Whitney U test. Univariate and multivariate logistic regression analyses were used to construct the nomogram of the AtM and AnM prediction model, and the model's predictive efficacy was evaluated using calibration and decision curves. Significant differences in the mean, enhancement, perc.01%, and edema were noted between the AtM and AnM groups (P < 0.05). Age, sex, location, necrosis, shape, max-D, variance, skewness, kurtosis, perc.10%, perc.50%, perc.90%, and perc.99% exhibited no significant differences (P > 0.05). The mean and enhancement were independent risk factors for distinguishing AtM from AnM. The area under the curve, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the nomogram were 0.871 (0.753-0.946), 80.0%, 81.0%, 79.4%, 70.8%, and 87.1%, respectively. The calibration curve demonstrated that the model's probability to predict AtM and AnM was in favorable agreement with the actual probability, and the decision curve revealed that the prediction model possessed satisfactory clinical availability. A logistic regression model nomogram based on conventional MRI features and ADC histogram parameters is potentially useful as an auxiliary tool for the preoperative differential diagnosis of AtM and AnM.

Practical Guideline for Prevention of Patchy Hair Loss following CyberKnife Stereotactic Radiosurgery for Calvarial or Scalp Tumors: Retrospective Analysis of a Single Institution Experience

INTRODUCTION

Patchy alopecia is a common adverse effect of stereotactic radiosurgery (SRS) on the calvarium and/or scalp, yet no guidelines exist for its prevention. This study aims to investigate the incidence and outcomes of patchy alopecia following SRS for patients with calvarial or scalp lesions and establish preventive guidelines.

METHODS

The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months.

RESULTS

Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found.

CONCLUSION

In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.

A rare case of a right infratentorial meningioma and a left giant posterior communicating thrombosed aneurysm

Background

Giant intracranial aneurysms cause symptoms due to mass effect and can mimic other lesions in imaging studies. The coexistence of tumors and aneurysms is relatively rare, with meningiomas being the predominant tumors found in such cases. The relationship between these two entities is complex and represent a neurosurgical challenge.

Case Description

A 61-year-old woman presented with intermittent headache, vertigo, right peripheral facial palsy, hearing loss, and left hemiparesis. Magnetic resonance imaging revealed two lesions: a supratentorial paraclinoid lesion in the left frontotemporal region and a right infratentorial extra-axial mass, suggestive of a meningioma. The patient underwent a two-staged surgical intervention to address both lesions.

Conclusion

In this particular case, the lesions were located on different sides and in different cranial compartments, making it even rarer.

Frailty and postoperative outcomes in brain tumor patients: a systematic review subdivided by tumor etiology

PURPOSE

Frailty has gained prominence in neurosurgical oncology, with more studies exploring its relationship to postoperative outcomes in brain tumor patients. As this body of literature continues to grow, concisely reviewing recent developments in the field is necessary. Here we provide a systematic review of frailty in brain tumor patients subdivided by tumor type, incorporating both modern frailty indices and traditional Karnofsky Performance Status (KPS) metrics.

METHODS

Systematic literature review was performed using PRISMA guidelines. PubMed and Google Scholar were queried for articles related to frailty, KPS, and brain tumor outcomes. Only articles describing novel associations between frailty or KPS and primary intracranial tumors were included.

RESULTS

After exclusion criteria, systematic review yielded 52 publications. Amongst malignant lesions, 16 studies focused on glioblastoma. Amongst benign tumors, 13 focused on meningiomas, and 6 focused on vestibular schwannomas. Seventeen studies grouped all brain tumor patients together. Seven studies incorporated both frailty indices and KPS into their analyses. Studies correlated frailty with various postoperative outcomes, including complications and mortality.

CONCLUSION

Our review identified several patterns of overall postsurgical outcomes reporting for patients with brain tumors and frailty. To date, reviews of frailty in patients with brain tumors have been largely limited to certain frailty indices, analyzing all patients together regardless of lesion etiology. Although this technique is beneficial in providing a general overview of frailty's use for brain tumor patients, given each tumor pathology has its own unique etiology, this combined approach potentially neglects key nuances governing frailty's use and prognostic value.

Efficacy of selective transarterial chemoembolization for recurred liver metastases from intracranial meningioma: A case report

Extracranial metastases from intracranial meningioma involve multiple organs with repeatedly recurrence. Due to the rarity of these metastases, management remains to be established, especially in cases that are not amenable to surgery, such as postsurgical relapse and multiple metastases. We present the case of a right tentorial meningioma with multiple extracranial metastases, including postsurgical recurrent liver metastases. The intracranial meningioma was surgically resected when the patient was 53 years of age. The patient was 66 years of age when the hepatic lesion was first revealed, for which an extended right posterior sectionectomy was performed. Histopathology demonstrated a metastatic meningioma. Twelve months after liver resection, multiple local recurrences in the right hepatic lobe were revealed. Because additional surgical resection would put the patient at risk of declining residual liver function, we performed selective transarterial chemoembolization, resulting in a reduction in size and good control without relapse. Selective transarterial chemoembolization for incurable liver metastatic meningiomas could be valuable in palliating patients unsuitable for surgery.

Preoperative Embolization of Meningiomas Facilitates Reduced Surgical Complications and Improved Clinical Outcomes : A Meta-analysis of Matched Cohort Studies

PURPOSE

The utility of preoperative embolization (PE) of intracranial meningiomas is unclear and controversial. The aim of this study was to investigate the effect of PE on meningioma surgical resection by completing a meta-analysis of matched cohort studies.

METHODS

A systematic review and meta-analysis of matched cohort studies was completed to evaluate the effect of PE on meningioma resection and outcomes. Outcome measures included: intraoperative blood loss, major surgical complications, total surgical complications including minor ones, total major complications including major surgical and embolization complications, total overall complications, and postoperative functional independence defined as modified Rankin Score (mRS) of 0-2. Pooled odds ratios (OR) were determined via a fixed effects model.

RESULTS

A total of 6 matched cohort studies were identified with 219 embolized and 215 non-embolized meningiomas. There was no significant difference in intraoperative blood loss between the two groups (P = 0.87); however, the embolization group had a significantly lower odds ratio of major surgically related complications (OR: 0.37, 95% confidence interval, CI: 0.21-0.67, P = 0.0009, I2 = 0%), but no difference in minor surgical complications (P = 0.86). While there was a significantly lower odds ratio of total overall surgical and PE-related complications in PE cases (OR: 0.64, CI: 0.41-1.0, P = 0.05, I2 = 66%), there was no difference in total combined major complications between the groups (OR: 0.57, CI: 0.27-1.18, P = 0.13, I2 = 33%). Lastly, PE was associated with a higher odds ratio of functional independence on postoperative follow-up (OR: 2.3, CI: 1.06-5.02, P = 0.04, I2 = 0%).

CONCLUSION

For certain meningiomas, PE facilitates lower overall complications, lower major surgical complications, and improved functional independence. Further research is required to identify the particular subset of meningiomas that benefit from PE.

Postoperative neurological complications in intradural extramedullary tumors: A 10-year experience of a single center

BACKGROUND

Intradural extramedullary spinal cord tumors (IDEMs) cause neurological symptoms due to compression of the spinal cord and caudal nerves. The purpose of this study was to investigate the incidence of postoperative neurological complications after surgical resection of IDEM and to identify factors associated with such postoperative neurological complications.

METHODS

We retrospectively analyzed 85 patients who underwent tumor resection for IDEM between 2010 and 2020. We investigated the postoperative worsening of neurological disorders. The patients were divided into two groups: those with and without postoperative neurological complications. Patient demographic characteristics, tumor level, histological type, and surgery-related factors were also compared.

RESULTS

The mean age at the time of surgery was 57.4 years, and histological analysis revealed 45 cases of schwannoma, 34 cases of meningioma, three cases of myxopapillary ependymoma, one case of ependymoma, one case of hemangioblastoma and one case of lipoma. There were five cases (5.8%) of postoperative neurological complications, and four patients improved within 6 months after surgery, and one patient had residual worsening. There were no statistically significant differences in age, sex, tumor location, preoperative modified McCormick Scale grade, histology, tumor occupancy, or whether fixation was performed in the presence or absence of postoperative neurological complications. All four cases of meningioma with postoperative neurological complications had preoperative neuropathy and meningiomas were located in the anterior or lateral thoracic spine.

CONCLUSIONS

Neurological complications after surgical resection for IDEM occurred in 5.8% of patients. Meningiomas with postoperative neurological complications located anteriorly or laterally in the thoracic spine.

Advancing personalized prognosis in atypical and anaplastic meningiomas through interpretable machine learning models

PURPOSE

The primary purpose of this study was to utilize machine learning (ML) models to create a web application that can predict survival outcomes for patients diagnosed with atypical and anaplastic meningiomas.

METHODS

In this retrospective cohort study, patients diagnosed with WHO grade II and III meningiomas were selected from the National Cancer Database (NCDB) to analyze survival outcomes at 12, 36, and 60 months. Five machine learning algorithms - TabPFN, TabNet, XGBoost, LightGBM, and Random Forest were employed and optimized using the Optuna library for hyperparameter tuning. The top-performing models were then deployed into our web-based application.

RESULTS

From the NCDB, 12,197 adult patients diagnosed with histologically confirmed WHO grade II and III meningiomas were retrieved. The mean age was 61 (± 20), and 6,847 (56.1%) of these were females. Performance evaluation indicated that the top-performing models for each outcome were the models built with the TabPFN algorithm. The TabPFN models yielded area under the receiver operating characteristic (AUROC) values of 0.805, 0.781, and 0.815 in predicting 12-, 36-, and 60-month mortality, respectively.

CONCLUSION

With the continuous growth of neuro-oncology data, ML algorithms act as key tools in predicting survival outcomes for WHO grade II and III meningioma patients. By incorporating these interpretable models into a web application, we can practically utilize them to improve risk evaluation and prognosis for meningioma patients.

Somatostatin receptor subtype expression and radiomics from DWI-MRI represent SUV of [68Ga]Ga-DOTATOC PET in patients with meningioma

OBJECTIVE

This retrospective study aimed to analyse the correlation between somatostatin receptor subtypes (SSTR 1-5) and maximum standardized uptake value (SUVmax) in meningioma patients using Gallium-68 DOTA-D-Phe1-Tyr3-octreotide Positron Emission Tomography ([68Ga]Ga-DOTATOC PET). Secondly, we developed a radiomic model based on apparent diffusion coefficient (ADC) maps derived from diffusion weighted magnetic resonance images (DWI MRI) to reproduce SUVmax.

METHOD

The study included 51 patients who underwent MRI and [68Ga]Ga-DOTATOC PET before meningioma surgery. SUVmax values were quantified from PET images and tumour areas were segmented on post-contrast T1-weighted MRI and mapped to ADC maps. A total of 1940 radiomic features were extracted from the tumour area on each ADC map. A random forest regression model was trained to predict SUVmax and the model's performance was evaluated using repeated nested cross-validation. The expression of SSTR subtypes was quantified in 18 surgical specimens and compared to SUVmax values.

RESULTS

The random forest regression model successfully predicted SUVmax values with a significant correlation observed in all 100 repeats (p < 0.05). The mean Pearson's r was 0.42 ± 0.07 SD, and the root mean square error (RMSE) was 28.46 ± 0.16. SSTR subtypes 2A, 2B, and 5 showed significant correlations with SUVmax values (p < 0.001, R2 = 0.669; p = 0.001, R2 = 0.393; and p = 0.012, R2 = 0.235, respectively).

CONCLUSION

SSTR subtypes 2A, 2B, and 5 correlated significantly with SUVmax in meningioma patients. The developed radiomic model based on ADC maps effectively reproduces SUVmax using [68Ga]Ga-DOTATOC PET.

Meningioma in the third trimester of pregnancy: A case report

Meningiomas are rare benign tumors during pregnancy. They can put both the mother and the fetus at risk because rapid changes in size may occur. The study reports a case of olfactory groove meningioma in a 34-year-old pregnant woman with visual impairment, anosmia, and dysgeusia that increased in severity during the 29th week of gestation. Magnetic resonance imaging showed an olfactory groove meningioma. The patient underwent a preterm cesarean section to avoid the worsening of the clinical condition due to intracranial compression phenomena. A computed tomography scan of the brain supported the diagnosis. The surgical intervention occurred on the third day after delivery. The clinical course was uneventful and the chiasmal syndrome improved in the following 2 months. Meningiomas in pregnancy may present unique challenges and have a wide array of clinical presentations. Management of maternal meningiomas can be complex and requires a multidisciplinary approach. The treatment decision largely depends on the size and location of the tumor, the presence of symptoms, gestational age, and fetal well-being. Further research is needed to enhance the understanding of the underlying mechanisms and improve management approaches for this rare condition.

Update on meningioma: Clinical-radiological and radio-pathological correlation

Meningiomas are tumors that originate in the arachnoid villi and are the most common non-glial neoplasm in the central nervous system. The clinical manifestations associated with meningioma depend, fundamentally, on its location. The location in the cerebral convexity is the most frequent, especially in the frontal lobes, manifesting with headache, motor disturbances, seizures and even neurocognitive disorders. There are 15 histologic subtypes of meningioma and three histologic grades. Within these, grades two and three have a worse prognosis and a higher rate of recurrence, as well as a radiological behavior that is generally more aggressive. Although there are some imaging features that can suggest a specific subtype, the definitive diagnosis will always require histological/molecular confirmation.

Next-generation PET/CT imaging in meningioma-first clinical experiences using the novel SSTR-targeting peptide [18F]SiTATE

BACKGROUND

Somatostatin-receptor (SSTR)-targeted PET/CT provides important clinical information in addition to standard imaging in meningioma patients. [18F]SiTATE is a novel, 18F-labeled SSTR-targeting peptide with superior imaging properties according to preliminary data. We provide the first [18F]SiTATE PET/CT data of a large cohort of meningioma patients.

METHODS

Patients with known or suspected meningioma undergoing [18F]SiTATE PET/CT were included. Uptake intensity (SUV) of meningiomas, non-meningioma lesions, and healthy organs were assessed using a 50% isocontour volume of interest (VOI) or a spherical VOI, respectively. Also, trans-osseous extension on PET/CT was assessed.

RESULTS

A total of 107 patients with 117 [18F]SiTATE PET/CT scans were included. Overall, 231 meningioma lesions and 61 non-meningioma lesions (e.g., post-therapeutic changes) were analyzed. Physiological uptake was lowest in healthy brain tissue, followed by bone marrow, parotid, and pituitary (SUVmean 0.06 ± 0.04 vs. 1.4 ± 0.9 vs. 1.6 ± 1.0 vs. 9.8 ± 4.6; p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6 ± 10.6 vs. 4.0 ± 3.3, p < 0.001). Meningiomas showed significantly higher uptake than non-meningioma lesions (SUVmax 11.6±10.6 vs. 4.0±3.3, p<0.001). 93/231 (40.3%) meningiomas showed partial trans-osseous extension and 34/231 (14.7%) predominant intra-osseous extension. 59/231 (25.6%) meningioma lesions found on PET/CT had not been reported on previous standard imaging.

CONCLUSION

This is the first PET/CT study using an 18F-labeled SSTR-ligand in meningioma patients: [18F]SiTATE provides extraordinary contrast in meningioma compared to healthy tissue and non-meningioma lesions, which leads to a high detection rate of so far unknown meningioma sites and osseous involvement. Having in mind the advantageous logistic features of 18F-labeled compared to 68Ga-labeled compounds (e.g., longer half-life and large-badge production), [18F]SiTATE has the potential to foster a widespread use of SSTR-targeted imaging in neuro-oncology.

Changes in incidence trends of meningioma in Finland, 1990-2017: analysis of Finnish Cancer Registry data

BACKGROUND

Meningiomas are the most common primary neoplasm of the central nervous system. Previous research on the incidence of meningioma in Finland showed an increase in the age-standardized incidence rate over three decades (1968-1997). In this study, we analysed meningioma incidence in Finland during 1990-2017.

MATERIALS AND METHODS

Data on 9842 meningioma patients were obtained from the Finnish Cancer Registry, and population size by calendar year, sex, and age group from Statistics Finland. The European Standard Population was used to calculate age-standardized incidence rates. Poisson regression was used to evaluate differences by sex and age, and joinpoint regression to examine changes in trend.

RESULTS

At the beginning of the study period, the age-standardized incidence of meningioma for men was 2.35/100,000 and for women 6.96/100,000. In the end, it was 4.09/100,000 and 10.19/100,000, respectively. The annual percent change (APC) for women was +4.6 (95% confidence interval, CI 3.10 to 6.20) from 1990 to 2001 and -1.0 (95% CI -1.70 to -0.30) from 2001 to 2017. For men, the APC was +3.1 (95% CI 0.80-5.40) during 1990-2002 and -0.9 (95% CI -2.10 to 0.30) in 2002-2017. The incidence of meningioma in women was 2.8 times higher than in men (rate ratio 2.81; 95% CI 2.68-2.94).

CONCLUSIONS

Meningioma incidence increased in both sexes from 1990, but the trend reversed in 2001-2002. Medical imaging or risk factors do not appear to explain the changes.

Decision-making tree for surgical treatment in meningioma: a geriatric cohort study

Controversies persist regarding the benefits of surgery in elderly patients with meningiomas. The objective of this study was to develop decision-making scale to clarify the necessity for surgical intervention and provide clinical consultation for this special population. This retrospective cohort study was conducted at a single center and included 478 elderly patients (≥ 65 years) who underwent meningioma resection. Follow-up was recorded to determine recurrence and mortality rates. Univariate and multivariate analyses were performed to identify significantly preoperative factors, and prognostic prediction models were developed with determined cutoff values for the prognostic index (PI). Model discrimination was evaluated using Kaplan-Meier curves based on the PI stratification, which categorized patients into low- and high-risk groups. A decision-making tree was then established based on the risk stratification from both models. Among all patients analyzed (n = 478), 62 (13.0%) experience recurrence and 47 (10.0%) died during the follow-up period. Significantly preoperative parameters from both models included advanced age, aCCI, recurrent tumor, motor cortex involvement, male sex, peritumoral edema, and tumor located in skull base (all P < 0.05). According to the classification of PI from the two models, the decision-making tree provided four recommendations that can be used for clinical consultation. Surgery is not recommended for patients assigned to the high-risk group in both models. Patients who meet the low-risk criteria in any model may undergo surgical intervention, but the final decision should depend on the surgeon's expertise.

Meningioangiomatosis with Skull Erosion

Meningioangiomatosis (MA) is a rare, poorly studied brain hamartomatous lesion, the etiology of which is not fully elucidated. It typically involves the leptomeninges, extending to the underlying cortex, characterized by small vessel proliferation, perivascular cuffing, and scattered calcifications. Given its close proximity to, or direct involvement of, the cerebral cortex, MA lesions typically manifest in younger patients as recurrent episodes of refractory seizures, comprising approximately 0.6% of operated-on intractable epileptic lesions. Due to the absence of characteristic radiological features, MA lesions constitute a significant radiological challenge, making them easy to miss or misinterpret. Although MA lesions are rarely reported with still-unknown etiology, it is prudent to be aware of these lesions for prompt diagnosis and management to avoid morbidity and mortality associated with delayed diagnosis and treatment. We present a case of a young patient with a first-time seizure caused by a right parieto-occipital MA lesion that was successfully excised via an awake craniotomy, achieving 100% seizure control.

Atypical radiological aspect of meningioma: Web-like enhancement

Meningiomas are the most common extra-axial neoplasmof the central nervous system (CNS). There are a number of characteristic imaging features of meningiomas on magnetic resonance imaging (MRI) that allow an accurate diagnosis, however there are a number of atypical features that may be diagnostically challenging. Furthermore, a number of other neoplastic and non-neoplastic conditions may mimic meningiomas. This case highlights the importance of careful analysis of imaging findings and the need for consideration of all possible diagnoses, including rare or atypical presentations of common neoplasms such as meningiomas. Early detection and accurate diagnosis are crucial in determining the appropriate management and improving the outcomes for patients with intracranial tumors.

Central nervous system manifestations of neurofibromatosis type 2: A case report

Neurofibromatosis type 2 (phacomatosis) is a rare inherited autosomal dominant condition defined by the development of numerous central neuronal tumors. In addition to classic intracranial schwannomas, intracranial and spinal meningiomas, and intramedullary ependymomas, it can be associated with a few cutaneous abnormalities. In this report, we discuss the case of a 21-year-old female who was examined for persistent headache with cutaneous masses and bilateral hearing loss. Magnetic resonance imaging of the cranium and the whole spine detected multiple meningiomas, intracranial, and intramedullary tumors.

Evaluation of four tumour growth models to describe the natural history of meningiomas

BACKGROUND

The incidence of newly diagnosed meningiomas, particularly those diagnosed incidentally, is continually increasing. The indication for treatment is empirical because, despite numerous studies, the natural history of these tumours remains difficult to describe and predict.

METHODS

This retrospective single-centre study included 294 consecutive patients with 333 meningiomas who underwent three or more brain imaging scans. Linear, exponential, power, and Gompertz models were constructed to derive volume-time curves, by using a mixed-effect approach. The most accurate model was used to analyse tumour growth and predictors of rapid growth.

FINDINGS

The Gompertz model provided the best results. Hierarchical clustering at the time of diagnosis and at the end of follow-up revealed at least three distinct groups, which can be described as pseudoexponential, linear, and slowing growth with respect to their parameters. Younger patients and smaller tumours were more frequent in the pseudo-exponential clusters. We found that the more "aggressive" the cluster, the higher the proportion of patients with grade II meningiomas and who have had a cranial radiotherapy. Over a mean observation period of 56.5 months, 21% of the tumours moved to a cluster with a lower growth rate, consistent with the Gompertz's law.

INTERPRETATION

Meningiomas exhibit multiple growth phases, as described by the Gompertz model. The management of meningiomas should be discussed according to the growth phase, comorbidities, tumour location, size, and growth rate. Further research is needed to evaluate the associations between radiomics features and the growth phases of meningiomas.

FUNDING

No funding.

A Nomogram Model for Stratifying the Risk of Recurrence in Patients with Meningioma After Surgery

BACKGROUND

Here, we aimed to investigate the clinical parameters affecting the recurrence of meningiomas, and to construct a predictive nomogram model, so as to predict the recurrence-free survival (RFS) of meningiomas more accurately.

METHODS

The Clinical, imaging, and pathological data of 155 primary meningioma patients treated surgically from January 2014 to March 2021 were retrospectively analyzed. Independent prognostic factors affecting postoperative recurrence of meningioma were identified by univariate and multivariate Cox regression analyses. A predictive nomogram was established based on independent influence parameters. Subsequently, time-dependent receiver operating characteristic curve, calibration curve, and Kaplan-Meier method were utilized to evaluate the predictive ability of the model.

RESULTS

The multivariate Cox regression analysis showed that tumor size, Ki-67 index, and resection extent had independent prognostic significance, and these parameters were subsequently used to construct a predictive nomogram. Receiver operating characteristic curves indicated that the model was more accurate in predicting RFS than independent factors. Calibration curves suggested that the predicted RFS were similar to the actual observed RFS. In the Kaplan-Meier analysis, the RFS of high-risk cases was obviously shorter than that of low-risk cases.

CONCLUSIONS

The tumor size, Ki-67 index, and extent of resection were independent factors affecting the RFS of meningioma. The predictive nomogram based on these factors can be used as an effective method to stratify the recurrence risk of meningioma and provide a reference for patients to choose personalized treatment.

Identification of the Key Immune Cells and Genes for the Diagnostics and Therapeutics of Meningioma

BACKGROUND

Dysregulation of immune infiltration critically contributes to the tumorigenesis and progression of meningiomas. However, the landscape of immune microenvironment and key genes correlated with immune cell infiltration remains unclear.

METHODS

Four Gene Expression Omnibus data sets were included. CIBERSORT algorithm was utilized to analyze the immune cell infiltration in samples. Wilcoxon test, Random Forest algorithm, and Least Absolute Shrinkage and Selection Operator regression were adopted in identifying significantly different infiltrating immune cells and differentially expressed genes (DEGs). Functional enrichment analysis was performed by Kyoto Encyclopedia of Genes and Genomes and Gene Ontology. The correlation between genes and immune cells was evaluated via Spearman's correlation analysis. Receiver Operator Characteristic curve analysis evaluated the markers' diagnostic effectiveness. The mRNA-miRNA and Drug-Gene-Immune cell interaction networks were constructed to identify potential diagnostic and therapeutic targets.

RESULTS

Plasma cells, M1 macrophages, M2 macrophages, neutrophils, eosinophils, and activated NK cells were the significantly different infiltrating immune cells in meningioma. A total of 951 DEGs, associated with synaptic function and structure, ion transport regulation, brain function, and immune-related pathways, were identified. Among 11 hub DEGs, RYR2 and TTR were correlated with plasma cells; SNCG was associated with NK cells; ADCY1 exhibited excellent diagnostic effectiveness; and ADCY1, BMX, KCNA5, SLCO4A1, and TTR could be considered as therapeutic targets.

CONCLUSIONS

ADCY1 can be identified as a diagnostic marker; ADCY1, BMX, KCNA5, SLCO4A1, and TTR are potential therapeutic targets, and their associations with macrophages, neutrophils, NK cells, and plasma cells might impact the tumorigenesis of meningiomas.

Hemostasis in a giant intraventricular tumor using a saline-cooled radiofrequency bipolar coagulator: technical note

BACKGROUND

Meningiomas are relatively rare in children and tend to be intraventricular and cystic, with often malignant behavior. Complete excision is associated with the most favorable outcome; moreover, the size and extent of these lesions often make complete excision in one step impossible because of the risk of intraoperative death from uncontrollable hemorrhage.

CASE PRESENTATION

A 10-year-old girl was admitted for headache in the last 3 months and was found to have a giant left intraventricular lesion with a volume of 166.63 cm3, which caused hydrocephalus and significant mass effect. Very large draining veins were evident within the tumor, draining into the thalamostriates and internal cerebral veins. Cerebral angiography showed multiple feeders originating mainly from branches of the posterior left choroidal artery with distal afferents that could not be embolized. Therefore, a left parietal transcortical approach was chosen. Given the vascularity of the tumor, saline-cooled radiofrequency coagulation (Aquamantys®) was used to reduce blood loss intraoperatively. Gross total resection (GTR) was achieved with an estimated blood loss of 640 mL. Pathology analysis was consistent with WHO grade 1 transitional meningioma. Postoperatively, the patient was neurologically intact, and MRI confirmed complete resection.

CONCLUSION

Aquamantys® is a novel bipolar coagulation device that employs a new bipolar coagulation technique combining radiofrequency energy and saline to achieve hemostatic sealing by denaturing collagen fibers. This offers the possibility of achieving adequate hemostasis even in giant intraventricular tumors in infants to obtain GTR resection with minimal blood loss.

A T-cell antigen atlas for meningioma: novel options for immunotherapy

Meningiomas are the most common primary intracranial tumors. Although most symptomatic cases can be managed by surgery and/or radiotherapy, a relevant number of patients experience an unfavorable clinical course and additional treatment options are needed. As meningiomas are often perfused by dural branches of the external carotid artery, which is located outside the blood-brain barrier, they might be an accessible target for immunotherapy. However, the landscape of naturally presented tumor antigens in meningioma is unknown. We here provide a T-cell antigen atlas for meningioma by in-depth profiling of the naturally presented immunopeptidome using LC-MS/MS. Candidate target antigens were selected based on a comparative approach using an extensive immunopeptidome data set of normal tissues. Meningioma-exclusive antigens for HLA class I and II are described here for the first time. Top-ranking targets were further functionally characterized by showing their immunogenicity through in vitro T-cell priming assays. Thus, we provide an atlas of meningioma T-cell antigens which will be publicly available for further research. In addition, we have identified novel actionable targets that warrant further investigation as an immunotherapy option for meningioma.

Multi-layered repair of high-flow CSF fistulae following endoscopic skull base surgery without nasal packing or lumbar drains: technical refinements to optimise outcome

AIMS

Post-operative CSF leak remains a significant problem following endoscopic skull base surgery, particularly when there is a high-flow intra-operative CSF leak. Most skull base repair techniques are accompanied by the insertion of a lumbar drain and/or the use of nasal packing which have significant shortcomings. Our aim was to review the results of a large series of endoscopic skull base cases where a high-flow intra-operative CSF leak rate was encountered and repaired to assess if modifications in technique could reduce the post-operative CSF leak rate.

METHODS

A retrospective review of a prospectively maintained database of skull base cases performed by a single surgeon over a 10-year period was performed. Data regarding patient demographics, underlying pathology, skull base repair techniques and post-operative complications were analysed.

RESULTS

One hundred forty-two cases with high-flow intra-operative CSF leak were included in the study. The most common pathologies were craniopharyngiomas (55/142, 39%), pituitary adenomas (34/142, 24%) and meningiomas (24/142, 17%). The CSF leak rate was 7/36 (19%) when a non-standardised skull base repair technique was used. However, with the adoption of a standardised, multi-layer repair technique, the post-operative CSF leak rate decreased significantly (4/106, 4% vs. 7/36, 19%, p = 0.006). This improvement in the rate of post-operative CSF leak was achieved without nasal packing or lumbar drains.

CONCLUSION

With iterative modifications to a multi-layered closure technique for high-flow intra-operative CSF leaks, it is possible to obtain a very low rate of post-operative CSF leak, without lumbar drains or nasal packing.

Olfaction preservation in olfactory groove meningiomas: a systematic review

Olfactory groove meningiomas (OGM) are a skull base neoplasm that represents between 8 and 13% of all intracranial meningiomas. Approach selection focuses on achieving frontal lobe decompression, gross total resection and vision preservation. Recently, there has been a focus on olfaction and considering its preservation as a quality-of-life outcome measure. An electronic search of the databases Medline, Scopus, Embase, Web of Science and Cochrane library databases was performed and data extracted according 2020 Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement. Six articles were selected for inclusion mainly based due to reporting quantitative outcomes for olfaction assessed by a smell identification test (e.g. sniffin' sticks). Objective olfaction preservation can be achieved with a variety of surgical approaches. More research which includes objective assessment of olfactory function and ideally as well QoL outcome measures is needed to further optimize the treatment pathways in OGM patients.