Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue of the dura mimicking meningioma: a case report and literature review.

MALT lymphoma of the dura is a very rare type of low-grade B-cell lymphoma. Little more than 100 cases have been reported in the literature to date. We report a 43-year-old woman who was referred to hospital because of a series of three tonic-clonic seizures on the day of admission. Neurological examination revealed confusion and aphasia. Magnetic resonance imaging (MRI) showed a contrast-enhanced, broad-based lesion along the dura in the left parieto-occipital area. The suspicion of an en plaque meningioma was raised. The tumour invaded the brain parenchyma with visible extension into the brain sulci. There was a marked brain oedema surrounding the lesion and causing the midline shift 8 mm to the right. After stabilization of neurological condition (intravenous diuretics and steroids), the operation was performed. The diagnosis of dural MALT lymphoma was established. During the pathological examination, it was especially problematic to distinguish MALT lymphoma from follicular lymphoma, but the final diagnosis was MALT lymphoma. Surgical partial removal with additional R-CVP immunochemotherapy (rituximab, cyclophosphamide, vincristine and prednisone) resulted in complete remission. The follow-up period is 1 year. Our presented case of a MALT lymphoma highlights the fact that surgical partial removal with additional immunochemotherapy is an available option in these rare intracranial tumours.

Tumors of the nervous system and hearing loss: Beyond vestibular schwannomas.

Hearing loss is a common side effect of many tumor treatments. However, hearing loss can also occur as a direct result of certain tumors of the nervous system, the most common of which are the vestibular schwannomas (VS). These tumors arise from Schwann cells of the vestibulocochlear nerve and their main cause is the loss of function of NF2, with 95 % of cases being sporadic and 5 % being part of the rare neurofibromatosis type 2 (NF2)-related Schwannomatosis. Genetic variations in NF2 do not fully explain the clinical heterogeneity of VS, and interactions between Schwann cells and their microenvironment appear to be critical for tumor development. Preclinical in vitro and in vivo models of VS are needed to develop prognostic biomarkers and targeted therapies. In addition to VS, other tumors can affect hearing. Meningiomas and other masses in the cerebellopontine angle can compress the vestibulocochlear nerve due to their anatomic proximity. Gliomas can disrupt several neurological functions, including hearing; in fact, glioblastoma multiforme, the most aggressive subtype, may exhibit early symptoms of auditory alterations. Besides, treatments for high-grade tumors, including chemotherapy or radiotherapy, as well as incomplete resections, can induce long-term auditory dysfunction. Because hearing loss can have an irreversible and dramatic impact on quality of life, it should be considered in the clinical management plan of patients with tumors, and monitored throughout the course of the disease.

Intra-operative extracorporeal irradiation of tumour-invaded craniotomy bone flap in meningioma: a case series.

BACKGROUND: Extracorporeal irradiation of tumorous calvaria (EITC) can be performed to restore function and form of the skull after resection of bone-invasive meningioma. We sought to examine the rate of tumour recurrence and other selected outcomes in patients undergoing meningioma resection and EITC. METHODS: Retrospective single-centre study of adult patients undergoing meningioma resection and EITC between January 2015 and November 2022 at a tertiary neurosurgical centre. Patient demographics, surgery data, tumour data, use of adjuvant therapy, surgical complications, and tumour recurrences were collected. RESULTS: Eighteen patients with 11 (61%) CNS WHO grade 1, 6 (33%) grade 2, and 1 (6%) grade 3 meningiomas were included. Median follow-up was 42 months (range 3-88). Five (28%) patients had a recurrence, but none were associated with the bone flap. Two (11%) wound infections requiring explant surgery occurred. Six (33%) patients required a further operation. Two operations were for recurrences, one was for infection, one was a washout and wound exploration but no evidence of infection was found, one patient requested the removal of a small titanium implant, and one patient required a ventriculoperitoneal shunt for a persistent CSF collection. There were no cases of bone flap resorption and cosmetic outcome was not routinely recorded. CONCLUSION: EITC is feasible and fast to perform with good outcomes and cost-effectiveness compared to other reconstructive methods. We observed similar recurrence rates and lower infection rates requiring explant compared to the largest series of cranioplasty in meningioma. Cosmetic outcome is universally under-reported and should be reported in future studies.

Atypical meningiomas compared to other WHO Grade 2 meningiomas: Histological features and prognosis.

OBJECTIVES: To study each atypical feature in atypical meningioma versus other grade 2 meningiomas and its possible relation to recurrence. METHODS: This is a retrospective study of patients with WHO grade 2 meningioma operated in our institution between 01/2008 and 12/2020. The rate of recurrence, reoperation and readmission were recorded during the follow-up period. A statistical analysis was done to determine the significance of each pathological feature in regard to recurrence. RESULTS: A total of 74 patients were included as WHO grade 2 meningioma with 60 (81%) patients having an AM and 14 (19%) patients with chordoid or clear cell meningioma. The mean age was 51 years±14. The most common location was meningioma abutting the frontal lobe (convexity). Major atypical features were more noted in the AM, however, there was no significant difference between AM and other types of meningioma. Increased Nuclear cytoplasmic ratio and cellularity were found significantly more in AM. The recurrence rate was 16.2%. No specific pathology feature (major or minor) nor the type of Grade 2 meningioma was significantly related to recurrence. CONCLUSION: The types of WHO grade 2 meningiomas have similar prognosis and recurrence rates. There is no significant difference between the atypical features in indicating a more aggressive nature or risk of recurrence in grade 2 meningiomas.

Descriptive epidemiology of 30,223 histopathologically confirmed meningiomas in France: 2006-2015.

BACKGROUND AND OBJECTIVES: Meningioma is one of the most common neoplasm of the central nervous system. To describe the epidemiology of meningioma operated in France and, to assess grading and histopathological variability among the different neurosurgical centres. METHODS: We processed the French Brain Tumour Database (FBTDB) to conduct a nationwide population-based study of all histopathologically confirmed meningiomas between 2006 and 2015. RESULTS: 30,223 meningiomas cases were operated on 28,424 patients, in 61 centres. The average number of meningioma operated per year in France was 3,022 (SD ± 122). Meningioma was 3 times more common in women (74.1% vs. 25.9%). The incidence of meningioma increased with age and, mean age at surgery was 58.5 ± 13.9 years. Grade 1, 2, and 3 meningiomas accounted for 83.9%, 13.91% and, 2.19% respectively. There was a significant variability of meningioma grading by institutions, especially for grade 2 which spanned from 5.1% up to 22.4% (p < 0.001). Moreover, the proportion of grade 2 significantly grew over the study period (p < 0.001). There was also a significant variation in grade 1 subtypes diagnosis among the institutions (p < 0.001). 89.05% of the patients had solely one meningioma surgery, 8.52% two and, 2.43% three or more. The number of surgeries was associated to the grade of malignancy (p < 0.001). CONCLUSION: The incidence of meningioma surgery increased with age and, peaked at 58.5 years. They were predominantly benign with meningothelial subtype being the most common. However, there was a significant variation of grade 1 subtypes diagnosis among the centres involved. The proportion of grade 2 meningioma significantly grew over the study time, on contrary to malignant meningioma proportion, which remained rare and, stable over time around 2%. Likewise, there was a significant variability of grade 2 meningioma rate among the institutions.

Clinical implications of DNA methylation-based integrated classification of histologically defined grade 2 meningiomas.

The combination of DNA methylation analysis with histopathological and genetic features allows for a more accurate risk stratification and classification of meningiomas. Nevertheless, the implications of this classification for patients with grade 2 meningiomas, a particularly heterogeneous tumor entity, are only partially understood. We correlate the outcomes of histopathologically confirmed grade 2 meningioma with an integrated molecular-morphologic risk stratification and determine its clinical implications. Grade 2 meningioma patients treated at our institution were re-classified using an integrated risk stratification involving DNA methylation array-based data, copy number assessment and TERT promoter mutation analyses. Grade 2 meningioma cases according to the WHO 2021 criteria treated between 2007 and 2021 (n = 100) were retrospectively analyzed. The median clinical and radiographic follow-up periods were 59.8 and 54.4 months. A total of 38 recurrences and 17 deaths were observed. The local control rates of the entire cohort after 2-, 4-, and 6-years were 84.3%, 68.5%, and 50.8%, with a median local control time of 77.2 months. The distribution of the integrated risk groups were as follows: 31 low, 54 intermediate, and 15 high risk cases. In the multivariable Cox regression analysis, integrated risk groups were significantly associated with the risk of local recurrence (hazard ratio (HR) intermediate: 9.91, HR high-risk: 7.29, p < 0.01). Gross total resections decreased the risk of local tumor progression (HR gross total resection: 0.19, p < 0.01). The comparison of 1p status and integrated risk groups (low vs. intermediate/high) revealed nearly identical local control rates within their respective subgroups. In summary, only around 50% of WHO 2021 grade 2 meningiomas have an intermediate risk profile. Integrated molecular risk stratification is crucial to guide the management of patients with grade 2 tumors and should be routinely applied to avoid over- and undertreatment, especially concerning the use of adjuvant radiotherapy.

Exploring the Biological Overlapping Between Brain Calcifications and Tumorgenesis.

This article discusses a rare case of coexistent meningiomas and Primary familial brain calcification (PFBC). PFBC is a neurodegenerative disease characterized by brain calcifications and a variety of neuropsychiatric symptoms and signs, with pathogenic variants in specific genes. The study explores the potential link between PFBC and meningiomas, highlighting shared features like intralesional calcifications and common genes such as MEA6. The article also revisits PFBC patients developing other brain tumors, particularly gliomas, emphasizing the intersection of oncogenes like PDGFB and PDGFRB in both calcifications and tumor progression. In recent investigations, attention has extended beyond brain tumors to breast cancer metastasis, unveiling a noteworthy connection. These findings suggest a broader connection between brain calcifications and tumors, encouraging a reevaluation of therapeutic approaches for PFBC.

Biomarkers for prognosis of meningioma patients: A systematic review and meta-analysis.

Meningioma is the most common primary brain tumor and many studies have evaluated numerous biomarkers for their prognostic value, often with inconsistent results. Currently, no reliable biomarkers are available to predict the survival, recurrence, and progression of meningioma patients in clinical practice. This study aims to evaluate the prognostic value of immunohistochemistry-based (IHC) biomarkers of meningioma patients. A systematic literature search was conducted up to November 2023 on PubMed, CENTRAL, CINAHL Plus, and Scopus databases. Two authors independently reviewed the identified relevant studies, extracted data, and assessed the risk of bias of the studies included. Meta-analyses were performed with the hazard ratio (HR) and 95% confidence interval (CI) of overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). The risk of bias in the included studies was evaluated using the Quality in Prognosis Studies (QUIPS) tool. A total of 100 studies with 16,745 patients were included in this review. As the promising markers to predict OS of meningioma patients, Ki-67/MIB-1 (HR = 1.03, 95%CI 1.02 to 1.05) was identified to associate with poor prognosis of the patients. Overexpression of cyclin A (HR = 4.91, 95%CI 1.38 to 17.44), topoisomerase II α (TOP2A) (HR = 4.90, 95%CI 2.96 to 8.12), p53 (HR = 2.40, 95%CI 1.73 to 3.34), vascular endothelial growth factor (VEGF) (HR = 1.61, 95%CI 1.36 to 1.90), and Ki-67 (HR = 1.33, 95%CI 1.21 to 1.46), were identified also as unfavorable prognostic biomarkers for poor RFS of meningioma patients. Conversely, positive progesterone receptor (PR) and p21 staining were associated with longer RFS and are considered biomarkers of favorable prognosis of meningioma patients (HR = 0.60, 95% CI 0.41 to 0.88 and HR = 1.89, 95%CI 1.11 to 3.20). Additionally, high expression of Ki-67 was identified as a prognosis biomarker for poor PFS of meningioma patients (HR = 1.02, 95%CI 1.00 to 1.04). Although only in single studies, KPNA2, CDK6, Cox-2, MCM7 and PCNA are proposed as additional markers with high expression that are related with poor prognosis of meningioma patients. In conclusion, the results of the meta-analysis demonstrated that PR, cyclin A, TOP2A, p21, p53, VEGF and Ki-67 are either positively or negatively associated with survival of meningioma patients and might be useful biomarkers to assess the prognosis.

Superficial meningioma with bone involvement: surgical strategies and clinical outcomes.

INTRODUCTION: Meningiomas with bone involvement account for 4.5-17% of all intracranial meningiomas. Little is known about whether these meningiomas (WHO grade I) behave differently than meningiomas without bone involvement. We sought to study the relatively uncommon imaging manifestations of meningioma and to evaluate their clinical significance. METHODS: A single-institution retrospective cohort study of surgically treated superficial meningioma patients between 2011 and 2022 was conducted. Age, sex, preoperative imaging, operative data, and surgical outcomes were reviewed. Imaging variables and outcomes were reported for patients with bone-invading meningiomas and compared with those with nonbone-invading meningiomas. Univariate analyses were also conducted. RESULTS: Of 577 total superficial meningiomas treated surgically, 47 (8.1%) exhibited bone invasion. Most bone-invading meningiomas were parasagittal (n = 29, 61.7%). A total of 12.7% (n = 6) of patients with bone-invading meningioma had recurrence, whereas 9.1% (n = 48) of patients with non-bone-invading meningioma had recurrence (p = 0.426). No significant difference in the median time to recurrence was observed between patients with bone-invading meningiomas and patients with nonbone-invading meningiomas (69.8 months, Q1:53.1; Q3:81.4 months vs. 69.7 months, Q1:47.5; Q3:96.7; p = 0.638). CONCLUSIONS: Superficial meningioma with bone involvement had similar outcomes compared to those of superficial meningioma without bone involvement. Hyperostosis in meningioma (WHO grade I) may not be a surrogate for aggressive meningioma behavior.

[Methylthioadenosine phosphorylase and p16 as surrogate diagnostic markers for CDKN2A homozygous deletion in brain tumors].

Objective: To examine whether immunohistochemistry of methylthioadenosine phosphorylase (MTAP) and p16 could be used to predict the CDKN2A status in various brain tumors. Methods: A total of 118 cases of IDH-mutant astrocytomas, 16 IDH-wildtype glioblastoma, 17 polymorphic xanthoastrocytoma (PXA) and 20 meningiomas diagnosed at Xuanwu Hospital, Capital Medical University, Beijing, China from November 2017 to October 2023 were collected and analyzed. The CDKN2A status was detected by using fluorescence in situ hybridization or next-generation sequencing. Expression of MTAP and p16 proteins was detected with immunohistochemistry. The association of loss of MTAP/p16 expression with CDKN2A homozygous/heterozygous deletion was examined. Results: Among the 118 cases of IDH-mutant astrocytoma, 13 cases showed homozygous deletion of CDKN2A. All of them had no expression of MTAP while 9 cases had no expression of p16. Among the 16 cases of IDH wild-type glioblastoma, 6 cases showed homozygous deletion of CDKN2A. All 6 cases had no expression of MTAP, while 3 of these cases had no expression of p16 expression. Among the 17 PXA cases, 4 cases showed homozygous deletion of CDKN2A, and the expression of MTAP and p16 was also absent in these 4 cases. Among the 20 cases of meningiomas, 4 cases showed homozygous deletion of CDKN2A. Their expression of MTAP and p16 was also absent. Among the four types of brain tumors, MTAP was significantly correlated with CDKN2A homozygous deletion (P<0.05), with a sensitivity of 100%. However, it was only significantly correlated with the loss of heterozygosity (LOH) of CDKN2A in astrocytomas (P<0.001). P16 was associated with CDKN2A homozygous deletion in IDH-mutant astrocytoma and PXA (P<0.001), but not with the LOH of CDKN2A. Its sensitivity and specificity were lower than that of MTAP. Conclusions: MTAP could serve as a predictive surrogate for CDKN2A homozygous deletion in adult IDH-mutant astrocytoma, PXA, adult IDH-wildtype glioblastoma and meningioma. However, p16 could only be used in the first two tumor types, and its specificity and sensitivity are lower than that of MTAP.

Meningioma achieves malignancy and erastin-induced ferroptosis resistance through FOXM1-AURKA-NRF2 axis.

The oncogene Aurora kinase A (AURKA) has been implicated in various tumor, yet its role in meningioma remains unexplored. Recent studies have suggested a potential link between AURKA and ferroptosis, although the underlying mechanisms are unclear. This study presented evidence of AURKA upregulation in high grade meningioma and its ability to enhance malignant characteristics. We identified AURKA as a suppressor of erastin-induced ferroptosis in meningioma. Mechanistically, AURKA directly interacted with and phosphorylated kelch-like ECH-associated protein 1 (KEAP1), thereby activating nuclear factor erythroid 2 related factor 2 (NFE2L2/NRF2) and target genes transcription. Additionally, forkhead box protein M1 (FOXM1) facilitated the transcription of AURKA. Suppression of AURKA, in conjunction with erastin, yields significant enhancements in the prognosis of a murine model of meningioma. Our study elucidates an unidentified mechanism by which AURKA governs ferroptosis, and strongly suggests that the combination of AURKA inhibition and ferroptosis-inducing agents could potentially provide therapeutic benefits for meningioma treatment.

FNA of Meningioma with Rhabdoid Features Presenting as a Lateral Neck Mass.

Primary meningioma at extracranial head and neck sites is uncommon. Since fine needle aspiration (FNA) is often the first line diagnostic modality for the evaluation of masses in the head and neck, extracranial meningiomas can create a significant diagnostic pitfall for FNA. We report a case of meningioma with rhabdoid features and BAP1 loss in a 26-year-old woman, presenting as a large neck mass along the carotid sheath. FNA biopsy of the mass demonstrated a highly cellular specimen with clusters of uniform, epithelioid cells with round to ovoid nuclei and moderate nuclear to cytoplasmic ratio. An extensive immunohistochemical panel performed on cell block sections showed that the tumor cells were weakly EMA positive, progesterone receptor was focally positive, and SSTR2A was diffuse and strongly positive. BAP1 immunohistochemistry showed a diffuse loss of expression in the tumor cells. After the cytologic diagnosis of meningioma, a tissue biopsy was performed, and the diagnosis of meningioma with rhabdoid features and BAP1 loss was confirmed. We also perform a literature review of meningioma cases presenting as a neck mass and evaluated by FNA. Our case highlights the significant diagnostic challenges that can be caused by extracranial meningiomas on FNA and the importance of ancillary studies to avoid diagnostic pitfalls.

Re-irradiation for recurrent intracranial meningiomas: Analysis of clinical outcomes and prognostic factors.

PURPOSE: Re-irradiation (re-RT) for recurrent intracranial meningiomas is hindered by the limited radiation tolerance of surrounding tissue and the risk of side effects. This study aimed at assessing outcomes, toxicities and prognostic factors in a cohort of patients with recurrent meningiomas re-treated with different RT modalities. MATERIALS AND METHODS: A multi-institutional database from 8 Italian centers including intracranial recurrent meningioma (RM) patients who underwent re-RT with different modalities (SRS, SRT, PT, EBRT) was collected. Biologically Equivalent Dose in 2 Gy-fractions (EQD2) and Biological Effective Dose (BED) for normal tissue and tumor were estimated for each RT course (α/ß = 2 for brain tissue and α/ß = 4 for meningioma). Primary outcome was second progression-free survival (s-PFS). Secondary outcomes were overall survival (OS) and treatment-related toxicity. Kaplan-Meier curves and Cox regression models were used for analysis. RESULTS: Between 2003 and 2021 181 patients (pts) were included. Median age at re-irradiation was 62 (range 20-89) and median Karnofsky Performance Status (KPS) was 90 (range 60-100). 78 pts were identified with WHO grade 1 disease, 65 pts had grade 2 disease and 10 pts had grade 3 disease. 28 pts who had no histologic sampling were grouped with grade 1 patients for further analysis. Seventy-five (41.4 %) patients received SRS, 63 (34.8 %) patients SRT, 31 (17.1 %) PT and 12 (6.7 %) EBRT. With a median follow-up of 4.6 years (interquartile range 1.7-6.8), 3-year s-PFS was 51.6 % and 3-year OS 72.5 %. At univariate analysis, SRT (HR 0.32, 95 % CI 0.19-0.55, p < 0.001), longer interval between the two courses of irradiation (HR 0.37, 95 % CI 0.21-0.67, p = 0.001), and higher tumor BED (HR 0.45 95 % CI 0.27-0.76, p = 0.003) were associated with longer s-PFS; in contrast, Ki67 > 5 % (HR 2.81, 95 % CI 1.48-5.34, p = 0.002) and WHO grade > 2 (HR 3.08, 95 % CI 1.80-5.28, p < 0.001) were negatively correlated with s-PFS. At multivariate analysis, SRT, time to re-RT and tumor BED maintained their statistically significant prognostic impact on s-PFS (HR 0.36, 95 % CI 0.21-0.64, p < 0.001; HR 0.38, 95 % CI 0.20-0.72, p = 0.003 and HR 0.31 95 % CI 0.13-0.76, p = 0.01, respectively). Acute and late adverse events (AEs) were reported in 38 (20.9 %) and 29 (16 %) patients. Larger tumor GTV (≥10 cc) was significantly associated with acute and late toxicity (p < 0.001 and p = 0.009, respectively). CONCLUSIONS: In patients with recurrent meningiomas, reirradiation is a feasible treatment option associated with acceptable toxicity profile. Prognostic factors in the decision-making process have been identified and should be incorporated in daily practice.

Ki-67 index as a predictive marker of meningioma recurrence following surgical resection.

BACKGROUND: Meningiomas are the most common primary intracranial tumors in adults. Although benign in a majority of cases, they have a variable clinical course and may recur even after a thorough surgical resection. Ki-67, a nuclear protein involved in cell cycle regulation, has been widely studied as a marker of cellular proliferation in various cancers. However, the prognostic significance of Ki-67 in meningiomas remains controversial. Here, we investigate the Ki-67 index, as a predictive marker of meningioma recurrence following surgical resection and compare it to established prognostic markers such as WHO grade and degree of resection. METHODS: The medical records of 451 patients with previously untreated cranial meningiomas who underwent resections from January 2011 to January 2021 at North Shore University Hospital (NSUH) were reviewed. Collected data included WHO grade, Ki-67 proliferative index, degree of resection - gross (GTR) vs subtotal (STR) - as judged by the surgeon, tumor location, and meningioma recurrence. This study was approved by the NSUH Institutional Review Board IRB 21-1107. RESULTS: There were 290 patients with grade I, 154 with grade II, and 7 with grade III meningiomas. The average post-resection follow-up period was 4 years, and 82 tumors (18 %) recurred. Higher WHO grades were associated with higher rates of recurrence, with rates of 11.4 %, 27.9 %, and 71.4 % for grades 1, 2, and 3, respectively, and subtotal resection corresponded to a higher rate of recurrence than total resection (34.3 % and 13.4 %, respectively). Higher WHO grades also correlated with higher Ki-67 scores (2.59, 10.01, and 20.71) for grades 1, 2, and 3, respectively. A multivariate logistic regression model identified Ki-67 and degree of resection as independent predictive variables for meningioma recurrence, with Ki-67 specifically predicting recurrence in the WHO grade II subset when analyzed separately for WHO grades I and II. CONCLUSION: Our 10-year retrospective study suggests that the Ki-67 index is an important predictive marker for recurrence of intracranial meningiomas following surgical resection, particularly among patients with WHO grade II tumors. Our findings add to a growing body of data that support inclusion of Ki-67 index in the WHO grading criteria for patients with meningiomas.

Perifocal edema is a risk factor for preoperative seizures in patients with meningioma WHO grade 2 and 3.

BACKGROUND: Patients with intracranial meningiomas frequently suffer from tumor-related seizures prior to resection, impacting patients' quality of life. We aimed to elaborate on incidence and predictors for seizures in a patient cohort with meningiomas WHO grade 2 and 3. METHODS: We retrospectively searched for patients with meningioma WHO grade 2 and 3 according to the 2021 WHO classification undergoing tumor resection. Clinical, histopathological and imaging findings were collected and correlated with preoperative seizure development. Tumor and edema volumes were quantified. RESULTS: Ninety-five patients with a mean age of 59.5 ± 16.0 years were included. Most tumors (86/95, 90.5%) were classified as atypical meningioma WHO grade 2. Nine of 95 tumors (9.5%) corresponded to anaplastic meningiomas WHO grade 3, including six patients harboring TERT promoter mutations. Meningiomas were most frequently located at the convexity in 38/95 patients (40.0%). Twenty-eight of 95 patients (29.5%) experienced preoperative seizures. Peritumoral edema was detected in 62/95 patients (65.3%) with a median volume of 9 cm3 (IR: 0-54 cm3). Presence of peritumoral edema but not age, tumor localization, TERT promoter mutation, brain invasion or WHO grading was associated with incidence of preoperative seizures, as confirmed in multivariate analysis (OR: 6.61, 95% CI: 1.18, 58.12, p = *0.049). Postoperative freedom of seizures was achieved in 91/95 patients (95.8%). CONCLUSIONS: Preoperative seizures were frequently encountered in about every third patient with meningioma WHO grade 2 or 3. Patients presenting with peritumoral edema on preoperative imaging are at particular risk for developing tumor-related seizures. Tumor resection was highly effective in achieving seizure freedom.

Meningioma: current updates on genetics, classification, and mouse modeling.

Meningiomas, the most common primary brain tumors in adults, are often benign and curable by surgical resection. However, a subset is of higher grade, shows aggressive growth behavior as well as brain invasion, and often recurs even after several rounds of surgery. Increasing evidence suggests that tumor classification and grading primarily based on histopathology do not always accurately predict tumor aggressiveness and recurrence behavior. The underlying biology of aggressive treatment-resistant meningiomas and the impact of specific genetic aberrations present in these high-grade tumors is still only insufficiently understood. Therefore, an in-depth research into the biology of this tumor type is warranted. More recent studies based on large-scale molecular data such as whole exome/genome sequencing, DNA methylation sequencing, and RNA sequencing have provided new insights into the biology of meningiomas and have revealed new risk factors and prognostic subtypes. The most common genetic aberration in meningiomas is functional loss of NF2 and occurs in both low- and high-grade meningiomas, whereas NF2-wildtype meningiomas are enriched for recurrent mutations in TRAF7, KLF4, AKT1, PI3KCA, and SMO and are more frequently benign. Most meningioma mouse models are based on patient-derived xenografts and only recently have new genetically engineered mouse models of meningioma been developed that will aid in the systematic evaluation of specific mutations found in meningioma and their impact on tumor behavior. In this article, we review recent advances in the understanding of meningioma biology and classification and highlight the most common genetic mutations, as well as discuss new genetically engineered mouse models of meningioma.

The trans-sylvian trans-petrosal "half & half" approach-a how I do it.

BACKGROUND: Petroclival meningiomas are one of the most challenging tumors to be operated in the realm of neurosurgery. Many approaches have been developed over the years. METHOD: The authors describe the Half & Half (H&H) approach whose main indication is petroclival meningiomas with suprasellar extension. The part of the tumor located above CN III and in the retrochiasmatic space is addressed through a trans-sylvian, while the petroclival portion is through an extradural anterior petrosectomy approach. The wide surgical corridor given by this approach allows extensive tumor resection while avoiding the risk associated with the manipulation of intracavernous neurovascular structures. CONCLUSION: The H&H approach is an effective strategy to maximize the safe resection of petroclival meningiomas.

Letter to editor: single-cell transcriptome analysis upon ECM-remodeling meningioma cells of published cases.

This letter offers a nuanced evaluation of the recent study on single-cell transcriptome analysis of ECM-remodeling meningioma cells. While acknowledging the positive aspects, such as enhanced understanding of tumor heterogeneity and identification of potential therapeutic targets, it also highlights potential limitations, including challenges in data interpretation and validation.The focus on ECM-remodeling may inadvertently overshadow other critical aspects of tumor biology, necessitating a more holistic approach. The abstract concludes by emphasizing the importance of considering the broader context of tumor heterogeneity and microenvironmental influences in future research endeavors to improve clinical outcomes for patients with meningioma and other malignancies.

Novel classification of foramen magnum meningiomas predicted by topographic position relative to neurovascular bundle.

PURPOSE: Proximity to critical neurovascular structures can create significant obstacles during surgical resection of foramen magnum meningiomas (FMMs) to the detriment of treatment outcomes. We propose a new classification that defines the tumor's relationship to neurovascular structures and assess correlation with postoperative outcomes. METHODS: In this retrospective review, 41 consecutive patients underwent primary resection of FMMs through a far lateral approach. Groups defined based on tumor-neurovascular bundle configuration included Type 1, bundle ventral to tumor; Type 2a-c, bundle superior, inferior, or splayed, respectively; Type 3, bundle dorsal; and Type 4, nerves and/or vertebral artery encased by tumor. RESULTS: The 41 patients (range 29-81 years old) had maximal tumor diameter averaging 30.1 mm (range 12.7-56 mm). Preoperatively, 17 (41%) patients had cranial nerve (CN) dysfunction, 12 (29%) had motor weakness and/or myelopathy, and 9 (22%) had sensory deficits. Tumor type was relevant to surgical outcomes: specifically, Type 4 demonstrated lower rates of gross total resection (65%) and worse immediate postoperative CN outcomes. Long-term findings showed Types 2, 3, and 4 demonstrated higher rates of permanent cranial neuropathy. Although patients with Type 4 tumors had overall higher ICU and hospital length of stay, there was no difference in tumor configuration and rates of postoperative complications or 30-day readmission. CONCLUSION: The four main types of FMMs in this proposed classification reflected a gradual increase in surgical difficulty and worse outcomes. Further studies are warranted in larger cohorts to confirm its reliability in predicting postoperative outcomes and possibly directing management decisions.

Deep learning and radiomics-based approach to meningioma grading: exploring the potential value of peritumoral edema regions.

Objective.To address the challenge of meningioma grading, this study aims to investigate the potential value of peritumoral edema (PTE) regions and proposes a unique approach that integrates radiomics and deep learning techniques.Approach.The primary focus is on developing a transfer learning-based meningioma feature extraction model (MFEM) that leverages both vision transformer (ViT) and convolutional neural network (CNN) architectures. Additionally, the study explores the significance of the PTE region in enhancing the grading process.Main results.The proposed method demonstrates excellent grading accuracy and robustness on a dataset of 98 meningioma patients. It achieves an accuracy of 92.86%, precision of 93.44%, sensitivity of 95%, and specificity of 89.47%.Significance.This study provides valuable insights into preoperative meningioma grading by introducing an innovative method that combines radiomics and deep learning techniques. The approach not only enhances accuracy but also reduces observer subjectivity, thereby contributing to improved clinical decision-making processes.