Chordoid Meningioma Research Articles

Comprehensive genomic analysis reveals clonal origin and subtype-specific evolution in a case of sporadic multiple meningiomas.

Meningioma is the most common primary intracranial tumor in adults, with up to 10% manifesting as multiple tumors. Data on the genomic and molecular changes in sporadic multiple meningiomas are scarce, leading to ongoing debates regarding their evolutionary processes. A comprehensive genetic analysis of a large number of lesions, including precursor lesions, is necessary to explore these two possible origins: clonal and independent. In the present study, we performed whole-exome sequencing and analyzed somatic single-nucleotide variants (SNVs), insertions/deletions (INDELs), and copy number alterations (CNAs) in a patient with sporadic multiple meningiomas. These meningiomas included two mass-forming lesions of different histological subtypes (transitional and chordoid) and two small meningothelial nests. Genetic analysis revealed CNAs on chromosomes 22q and Y as common abnormalities in the two largest tumors. Furthermore, we identified SNV/INDELs unique to each focus, with NF2 mutation prevalent in the transitional meningioma and CREBBP mutation in the chordoid meningioma. Loss of chromosome 22 was detected in two small meningothelial nests. Overall, we elucidated the clonal origin and subtype-specific evolution of multiple meningiomas in this case. CNAs may serve as the initial driving event in meningioma development.

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

To study each atypical feature in atypical meningioma versus other grade 2 meningiomas and its possible relation to recurrence. 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. 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. 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.

TREATMENT OF INTRAPARENCHYMAL CHORDOID MENINGIOMA:
 A CLINICAL CASE

Relevance: Meningioma has many forms, each with a specific histological structure and treatment tactics. Meningiomas are the most
 common intracranial neoplasms, most of which have an extracerebral location, and their intraparenchymal location is rare.
 The purpose was to describe a case of treatment of intraparenchymal chordoid meningioma.
 Methods: The article describes a case of treatment of intraparenchymal chordoid meningioma, which is rare in localization, structure, and
 possible combination with other systemic diseases.
 Results: Patient B. was admitted to the clinic for surgical treatment for an intracranial neoplasm; the main complaints were the presence
 of seizures and their transition to epileptic status. The tumor was removed completely, after which it was sent for further histological and
 immunohistochemical examination. The examination of micro slides revealed the presence of chordoid meningioma in the patient. In the
 postoperative period, as well as at control examination after 3 months, the patient showed a decrease in the number of seizures and no transition
 to epileptic status. MRI control showed no relapse of tumor growth.
 Conclusion: WHO classifies chordoid meningioma as a rare grade II meningioma. Chordoid meningioma often requires further radiation
 therapy, especially with partial or subtotal removal, due to a slightly higher risk of relapse compared to grade I meningiomas. This disease can
 occur independently or in association with Castleman syndrome and can be asymptomatic for a long time; this requires further follow-up of
 the patient.

Chordoid Meningioma with Extensive Lymphocytic Infiltration Forming Lymphoid Follicles: A Case Report

Chordoid Meningioma with Extensive Lymphocytic Infiltration Forming Lymphoid Follicles: A Case Report

Skull base chordoid meningioma: a case with confounding imaging features

No abstract available

11C‐MET PET and 18F‐FDG PET characteristics of chordoid meningioma

A 17-year-old female patient presented to the neurology department with a 3-month history of left limb numbness and spasm with transient loss of consciousness 3 weeks earlier. A brain MRI revealed a right temporal lobe mass (Figure 1a, arrow) with hypointensity on T1WI, hyperintensity on T2WI, and no diffusion restriction on DWI and ADC mapping. The lesion showed minimal tracer uptake on 18F-FDG PET (Figure 1b, solid arrowhead) but avid uptake on 11C-MET PET with an SUVmax of 5.7 (Figure 1c, hollow arrowhead) with the contralateral normal tissue as a reference, suggesting a benign tumor other than inflammatory granuloma or malignant tumor. After conservative treatment with hormone and antiepileptic drugs, the patient's symptoms significantly improved. At the 3-month follow-up, the patient presented again with seizures of the left upper limb and transient loss of consciousness. She underwent mass excision in the neurosurgery department. Histopathology (Figure 1d) revealed a neoplasm with cords or trabeculae of small epithelioid to vacuolated cells embedded in a mucin-rich matrix, characteristic of chordoid meningioma (WHO grade 2), a rare type of meningioma [1-3. Immunostaining for SSTR-2 (Figure 1e), EMA, and PR showed strong reactivity in the tumor cells, and the MIB-1 labeling index was about 1%. Postoperative recovery was good, and no positive symptoms were found during a 5-year follow-up period [4]. This case report highlights the need to consider intracranial chordoid meningioma as a differential diagnosis when there is a discrepancy in the extent of tracer uptake on 11C-MET and 18F-FDG PET [5, 6]. Brain MRI, 11C-MET PET, 18F-FDG PET and histopathological findings in a 17-year-old female patient with chordoid meningioma. (a) A right temporal lobe mass (arrow) was revealed on brain MRI. (b) The mass showed minimal tracer uptake on 18F-FDG PET (solid arrowhead). (c) Avid uptake was found on 11C-MET PET (hollow arrowhead). (d) The mass was proved to be a chordoid meningioma by postoperative pathology. (e) Immunostaining for SSTR-2, EMA, and PR showed strong reactivity in the tumor cells. Leilei Yuan: Writing – original draft (Lead). Mengyan Zhang: Writing – original draft (Equal). Li Xu: Resources (Supporting). Xin Wang: Writing – original draft (Supporting). Qian Chen: Writing – review & editing (Supporting). Lin Ai: Writing – review & editing (Lead). None. The authors declare no conflicts of interest. None. None. The data that supports the findings of this study are available in the supplementary material of this article.

Unilateral Orbitopathy Caused by Skull Base Chordoid Meningioma

Chordoid meningioma (CM) makes up only 1% of all meningiomas. Most cases of this variant are locally aggressive, have high growth potential, and are likely to recur. Although CMs are known to be invasive, they rarely extend into the retro-orbital space. Herein, we report a case of a central skull base CM in a 78-year-old woman whose only manifestation was unilateral proptosis with impaired vision resulting from the tumor extending into the retro-orbital space through the superior orbital fissure. The diagnosis was confirmed by analysis of specimens collected during endoscopic orbital surgery, which simultaneously relieved the protruding eye and restored the patient's visual acuity by decompressing the oppressed orbit. This rare presentation of CM reminds physicians there may be lesions outside the orbit that can cause unilateral orbitopathy and that endoscopic orbital surgery can be used to confirm its diagnosis as well as treat it.

Epithelial membrane antigen-reactive feline chordoid meningioma in a European wildcat (Felis silvestris)

Meningioma is the most frequent intracranial neoplasm in cats. Here we describe the first case of chordoid meningioma (CM), a rare grade II meningioma subtype, in a 5.5-year-old European wildcat (Felis silvestris) from a Swiss zoo. The wildcat was found dead after a clinical history of neurological signs and clinical suspicion of a carcinoma in the right external ear canal with concurrent chronic otitis. Post-mortem examination revealed a large intracranial, extra-axial and intradural neoplasm that invaded into the right ear canal and had histological features compatible with CM, which has been only reported in humans and dogs. Neoplastic cells expressed vimentin but were negative for glial fibrillary acidic protein, S100 and pancytokeratin. Immunohistochemistry revealed epithelial membrane antigen (EMA) expression in neoplastic cells. To the best of our knowledge, we provide the first evidence of EMA expression in feline meningioma.

Rare case of extracranial chordoid meningioma adjacent to the carotid sheath: illustrative case.

Chordoid meningioma is a rare World Health Organization (WHO) grade 2 variant of meningioma with histological features resembling those of a chordoma. This tumor type is known for having an aggressive clinical course with a propensity for local recurrence. Most cases occur within the cranium, more specifically around the cerebral convexities. Although extracranial meningiomas of various subtypes have been documented, extracranial meningioma with a chordoid subtype is an extremely rare entity. The authors herein report the case of a 51-year-old female who presented with a chief complaint of dysphagia and was found to have a neck mass abutting the carotid sheath. The patient underwent resection and final pathology results revealed a WHO grade 2 chordoid meningioma. This case report demonstrates an atypical case of an extracranial chordoid meningioma adjacent to the carotid sheath. To the authors' knowledge, this is the first reported case of a chordoid meningioma occurring within the soft tissue of the neck.

Favorable Long-Term Outcomes of Chordoid Meningioma Compared With the Other WHO Grade 2 Meningioma Subtypes.

WHO grade 2 meningiomas, including atypical, chordoid, and clear cell subtypes, form a heterogenous group of meningiomas with varying aggressiveness and clinical behavior. To demonstrate the differences of clinical-histopathological characteristics and long-term outcomes among these 3 subtypes. A total of 609 consecutive patients diagnosed with WHO grade 2 meningiomas (543 atypical meningiomas [AMs], 36 chordoid meningiomas [CMs], and 30 clear cell meningiomas [CCMs]) from 2010 to 2018 were enrolled in this study. We compared the clinical-histopathological characteristics and long-term outcomes in these 3 subtypes and assessed survival differences among the subtypes. Targeted panel sequencing of meningioma-relevant genes was performed in the cases of CM. The patients with CCM were significantly younger than those with AM ( P < .001) and CM ( P = .016). CMs were more likely to receive gross total resection than AMs and CCMs ( P = .033). The Ki-67 index was lower ( P < .001) while the progesterone receptors-positive rate was higher ( P = .034) in CM than in AM and CCM. Importantly, survival analysis demonstrated that CM had better progression-free survival ( P = .022) and overall survival ( P = .0056) than non-CM tumors. However, the PFS of CM was still worse than WHO grade 1 meningiomas ( P < .001). Alterations in NF2 (20.6%) and KMT2C (26.5%) were associated with poorer PFS in CM ( P = .013 for NF2 ; P = .021 for KMT2C ). Patients with CM had better long-term postoperative outcomes than the other WHO grade 2 subtypes. A lower Ki-67 index, higher PR status, higher extent of resection, and lower frequency of NF2 alteration might contribute to favorable clinical outcomes of CM.

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

Chordoid meningioma (CM) is an infrequent histologic subtype of meningiomas. Owing to its low occurrence, this subtype has been rarely described. Our subject was to explore the clinical features, radiological characteristics, and prognostic factors of primary intracranial chordoid meningioma. We reviewed the medical records and collected follow-up information of 34 cases who had been surgically treated and histologically diagnosed with CM at the Department of Neurosurgery, West-China Hospital of Sichuan University, from January 2009 to December 2021. Among all 7,950 meningioma cases, the proportion of primary intracranial CM was 0.43% (34/7,950). The median diagnosis age was 47 (ranging from 12 to 74) and the gender ratio (male to female) was 2.1:1. For radiological features, heterogeneous enhancement, skull base, and ventricular localization, cystic degeneration and dural tail sign were common in CM cases. In treatment, gross total resection (GTR) was achieved in 22/34 cases (64.7%) and subtotal resection (STR) was achieved in 12/34 cases (35.3%). Further, 11/34 patients (32.4%) had received postoperative adjuvant radiotherapy (RT). The follow-up duration ranged from 4 to 157 months after operation. The progression rate was 20.7% (6/29) and the median of PFS was 38 months. By survival analysis, accepting adjuvant radiotherapy and achieving GTR were correlated with longer progression-free survival for prognosis. CM is a rare subtype of meningiomas. In our series, it mainly involved adults and did not show a predilection for women compared with meningiomas in general. For a better prognosis, gross total resection and postoperative adjuvant radiotherapy are recommended. Nevertheless, due to the restriction of the series sample, patients lost for follow-up and inherent biases of a retrospective study, more cases and a shorter follow-up duration are needed for better management of chordoid meningioma.

Epigenetic and genomic profiling of chordoid meningioma: implications for clinical management

Chordoid meningioma is a morphological variant of meningioma designated as WHO grade 2. However, the recurrence rates varied widely in different case series, and to date, a unifying molecular genetic signature has not been identified. Among 1897 meningiomas resected at our institution, we identified 12 primary chordoid meningiomas from 12 patients. Histologically, all 12 cases had predominant (> 50%) chordoid morphology. Ten were otherwise grade 1, and two were also atypical. We performed DNA global methylation profile, copy number variation analysis, and targeted next-generation sequencing on 11 chordoid meningiomas, and compared to those of 51 non-chordoid, mostly high grade meningiomas. The chordoid meningiomas demonstrated a unique methylation profile in tSNE, UMAP, and hierarchical heatmap clustering analyses of the most differentially methylated CpGs. The most common copy number variation in chordoid meningioma was loss of 1p (7/11, 64%). Three chordoid meningiomas had 2p loss, which was significantly higher than the non-chordoid control cohort (27% vs 7.2%, p = 0.035). 22q loss was only seen in the two cases with additional atypical histological features. Chordoid meningiomas were enriched in mutations in chromatin remodeling genes EP400 (8/11,73%) KMT2C (4/11, 36%) and KMT2D (4/11, 36%), and showed low or absent NF2, TERT, SMO, and AKT1 mutations. Prognosis wise, only one case recurred. This case had atypical histology and high-grade molecular features including truncating NF2 mutation, 1p, 8p, 10, 14, 22q loss, and homozygous deletion of CDKN2A/B. Progression free survival of chordoid, otherwise grade 1 meningioma was comparable to non-chordoid WHO grade 1 meningioma (p = 0.75), and significantly better than chordoid WHO grade 2 meningioma (p = 0.019). Conclusion: the chordoid histology alone may not justify a universal WHO grade 2 designation. Screening for additional atypical histological or molecular genetic features is recommended.

Tumour infiltrating lymphocyte density differs by meningioma type and is associated with prognosis in atypical meningioma

Tumour infiltrating lymphocyte (TIL) density is prognostically significant in various tumours, but few studies have investigated its significance in meningioma. This study aimed to investigate how TIL density differs by meningioma histology and whether it is a predictor of meningioma recurrence. We studied CD3, CD8, CD4, FOXP3 and PD-1 positive (+) TIL density in a continuous cohort of 476 meningiomas resected at Auckland Hospital between 2002 and 2011 using tissue microarrays and computer assisted image analysis. TILs were identified in all meningiomas except one (median CD3+ TIL density across entire cohort 53.0 cells/mm2). Most TILs were CD8+ (median 33.6 cells/mm2) with smaller numbers of CD4+ TILs (median 2.9 cells/mm2). PD-1+ (median 0.32 cells/mm2) and FOXP3+ (median 0.0 cells/mm2) TILs were scarce. Reduced CD3+ (p=0.0066), CD8+ (p=0.0029) and PD-1+ (p=0.0375) TIL density was seen in WHO grade II/III meningioma compared with WHO grade I. Pairwise comparison confirmed statistically significant differences in TIL density existed between meningioma types (CD3, CD8, CD4, p<0.0001; FOXP3, p=0.0096; PD-1, p=0.0090) with chordoid meningioma having the lowest overall CD3+ TIL density (median 12.5 cells/mm2). Despite its low TIL density, chordoid meningioma had a higher FOXP3:CD8 ratio than several meningioma types. Atypical meningioma had a higher FOXP3:CD8 ratio than transitional meningioma (p=0.0045). No association between TIL density and recurrence was seen across the entire cohort or by WHO grade. However, CD3+ and CD8+ TIL density was associated with recurrence in atypical meningioma on multivariable analysis (CD3, p=0.0012; CD8, p=0.0071). A higher CD3+ and CD8+ TIL density was associated with improved recurrence free survival. Our findings suggest CD3+ and CD8+ TIL density is prognostically significant in atypical meningioma. Further investigation of this observation and its biological basis is warranted. The differences in TIL density by meningioma histology may be of relevance in studies of therapeutic immune checkpoint inhibition.

Progestin-related WHO grade II meningiomas behavior-a single-institution comparative case series.

WHO grade II progestin-related meningiomas have been reported in recent series but we found no previous study describing their long-term outcome. Our study aimed to evaluate patients operated on for high-grade intracranial meningioma and who underwent long-term exposure to high dose of cyproterone acetate, nomegestrol acetate, and chlormadinone acetate. Our study retrospectively included 9 patients with high-grade progestin-related intracranial meningioma between December 2006 and September 2021. In each patient, clinico-radiological follow-up was performed every 6months after diagnosis and treatment withdrawal recommendation. The mean progestative exposure was 11.4years. Edema existence or absence of cleft sign on MRI were the key factors for surgical indication. All patients underwent surgery. Adjuvant radiotherapy was indicated in 1 patient, and Gamma Knife radiosurgery was proposed in 2 other patients for a second location of meningioma. Six patients harbored a grade II chordoid meningioma subtype with 100% PR expression and 3 patients a grade II atypical meningioma subtype with lower PR expression. The mean follow-up was 8.1years and none of the 9 patients presented with a recurrence. Patients with grade II progestin-related meningiomas have less tumor recurrence after surgery than patients with sporadic grade II meningiomas, especially after progestin withdrawal. The presence/appearance of peri-meningioma edema and the absence of cleft sign before volumetric change should suggest the existence of an underlying WHO grade II meningiomas. In these cases, surgical resection may immediately be considered and adjuvant radiotherapy should be reserved for proven recurrence cases.

Cordoid Meningioma A Case Report

Introduction: Meningiomas are tumors of the central nervous system derived from the arachnoid layer of cells, represent less than 3% of all primary intracranial tumors in children, are prevalent in adolescents, and are rare in younger ages. Pediatric cases represent approximately 1.5% of all intracranial meningiomas, and very few cases show aggressive histology. The WHO classification meningioma divided into three grades: Grade I benign; II, atypical; and III, anaplastic / malignant. Chordoid meningioma grade II / atypical meningioma is a rare subtype, which represents only 0.5% of all meningiomas, have high growth rates, higher recurrence and greater possibilities to invade the brain parenchyma compared with meningiomas benign. One possible explanation for the high recurrence rate may be related to the quality mucoid stroma, which facilitates extension of tumor and makes it difficult to achieve a complete resection, which leads to subsequent recurrence. Case Report: We report the case of male patient 4 years of age diagnosed with meningioma Grade II, with clinic 2 months of evolution who presented progressive neurological deterioration, tumoral exeresis was performed in 3 opportunities and placement system ventriculo peritoneal in the course of 1 month and radiotherapy. Comments: Accurate diagnosis, therefore, assumes importance because these tumors have an aggressive clinical course and high probability of recurrence so knowing the pathological Clinical Aspects of this rare neoplasm is essential for the Treatment and Comprehensive monitoring.

Primary Dural Repair Using Titanium Microclips Following Lateral Skull Base Surgery

Objective Standard techniques for primary dural repair following lateral skull base surgery are both technically challenging and time consuming without the potential for primary dural repair. Inadequate closure may result in postoperative cerebrospinal fluid (CSF) leak infectious sequalae. Traditional methods of dural repair rely on secondary obliteration of the CSF fistula. We hypothesized that the use of nonpenetrating titanium microclips may serve as a useful adjunct in primary dural repair or the establishment of an immobile repair layer following lateral skull base surgery. Methods Here, we report a novel technique for primary dural repair using nonpenetrating titanium microclips as an adjunct to standard techniques in a series of six patients with lateral skull base pathologies. Results A total of six consecutive lateral skull base tumor patients with titanium microclip dural reconstruction were included in our case series. Lateral skull base pathologies represented in this group included two jugular foramen schwannomas, one vestibular schwannoma, one petroclival meningioma, one glomus jugulare paraganglioma, and one jugular foramen chordoid meningioma. Conclusion To our knowledge, this is the first report on the use of microclips in repairing dural defects following lateral skull base surgery. Surgical outcomes for this small case series suggest that dural repair of the later skull base with nonpenetrating titanium microclips is a useful adjunct in dural repair following lateral skull base surgery.

Utility of multiparametric pre-operative magnetic resonance imaging in differentiation of chordoid meningioma from the other histopathological subtypes of meningioma-a retrospective study.

To determine the magnetic resonance imaging (MRI) features which could pre-operatively differentiate chordoid meningioma (CM) from other histopathological subtypes of meningioma. Retrospective analysis of pre-operative MRI of cases with histopathologically confirmed diagnosis of meningioma during the last 5 years at our institute was done. T1W, T2W, FLAIR sequences, and post-contrast enhancement were evaluated on a qualitative scale. Normalized ADC ratios (nADCR) and normalized fractional anisotropy ratios (nFAR) were derived. The intratumoral susceptibility score (ITSS), presence of sunburst pattern of vasculature, bone changes, tumour-parenchyma interface, and oedema-to-tumour ratio were also determined. A total of 81 lesions were analyzed out of which 15 were CM. CM showed a higher relative contrast enhancement as compared to all other subtypes except for angiomatous and microcystic meningioma. Relative signal intensity on FLAIR could differentiate CM from transitional meningioma. nFAR was found to be significantly higher in fibroblastic meningioma and significantly lower in microcystic meningiomas as compared to CM. Anaplastic meningiomas were remarkable for bone changes and an ill-defined tumour-brain interface in significantly higher proportion of cases as compared to CM. nADCR > 1.5 was found to be an independent predictor of CM with a sensitivity of 84.6%, specificity of 89.8%, positive predictive value of 64.7%, and negative predictive value of 96.4%. Routine pre-operative MRI may be able to differentiate CM from other meningioma subtypes and a cut-off value of greater than 1.5 for nADCR could be predictive of > 50% chordoid histology of meningioma with a high sensitivity, specificity, and negative predictive value.

Combined Transcavernous and Kawase's Approach for Gross Total Resection of a Cavernous Sinus Meningioma.

Microsurgery of cavernous sinus (CS) lesions is generally considered to be associated with a high rate of morbidity and cranial nerve deficits. The success for surgical removal of CS meningiomas is debatable and achieving a good functional outcome with preservation of the cranial nerves is the goal. Surgery of these lesions is challenging, recurrence rates are high, and therapeutic strategies remain controversial. In this video, we present a case of a CS meningioma that extended to Meckel's cave and the posterior fossa in a 46-year-old woman with history of a left-sided cerebellopontine angle World Health Organization (WHO) grade-I meningioma with extension to the left CS. Seven years ago, she had a microsurgical resection of a Cerebellopontine angle (CPA) meningioma. She later received radiotherapy for the slowly growing meningioma of the posterior CS. The patient presented with newly onset headache and facial pain. Magnetic resonance imaging (MRI) showed a meningioma of the left CS and Meckel's cave extending into the ambient cistern, with a mild mass effect on the pons, and a size increase compared with prior imaging. Since this area previously received radiotherapy, and the patient was symptomatic from trigeminal compression, the decision was made to proceed with surgical resection of the tumor via combined transcavernous and anterior petrosectomy. Postoperatively, the patient woke up with the same neurological status. MRI confirmed gross total resection of the tumor. The histopathology was a WHO grade-II chordoid meningioma. The patient is currently receiving radiotherapy. This video demonstrates the surgical approach and the resection steps of this pathology. The link to the video can be found at: https://youtu.be/HrU1VOzUGWU .

Gross Total Resection of a Recurrent in-and-around Cavernous Sinus Meningioma through a Combined Transcavernous Anterior and Middle Infratemporal Fossa Approach with Extracranial-Intracranial Bypass.

Objectives The study aims to describe surgical management of an invasive cavernous sinus meningioma with a combination of several skull base approaches and bypass surgery. Design This study is an operative video. Results Resection of the recurrent skull base meningioma is still challenging, especially if the tumor involves or encases the carotid artery. Cerebral bypass surgery is an essential adjunct in the armamentarium of skull base surgery when vessel reconstruction is required. In this paper, we describe our experience of successful treatment of an invasive recurrent skull base meningioma, which involved the entire cavernous sinus and the internal carotid artery. A 46-year-old woman presented with a 2-year history of gradually worsening left-sided exophthalmos and visual impairment. The patient had previously undergone two craniotomies for resection of the left-sided spheno-orbital meningioma. Pathological diagnosis was chordoid meningioma, which is classified as an intermediate-grade meningioma. The second surgery had been performed for a rapid tumor regrowth 6 months after the first surgery. The patient lost her left-side vision after the second surgery. Aggressive tumor regrowth was confirmed with extension into the left orbit, infratemporal fossa, and cavernous sinus with engulfment of the carotid artery. A balloon occlusion test revealed intolerance of the left internal carotid artery occlusion. Considering the patient's age, tumor behavior, and intolerance of the carotid artery of the lesion side, we scheduled gross total resection of the tumor with vessel reconstruction. Conclusion Although cerebral bypass surgery is a technically challenging procedure, it plays an important role in the surgical management of the complex vessel-engulfing tumor. The link to the video can be found at https://youtu.be/GCmpxK3hW18 .

Chordoid meningioma: report of 5 cases and review of the literature

Chordoid meningioma is a rare, more aggressive subtype of meningioma. This study documents the histological, radiological and clinical features of seven tumours in five patients among 131 meningioma patients who were treated in the Department of Neurosurgery at Istanbul Medipol University between 2014 and 2019. There were two males and three females. All tumours were supratentorial. Surgical Simpson grade II resection was achieved in two cases, grade I in one and grade IV in two. One case relapsed and underwent further surgeries and adjuvant treatment. The chances of survival without recurrence after the Simpson grade I–II resection are high but close follow-up is recommended particularly if grade I cannot be achieved.