Immunohistochemical profile of the dural tail in intracranial meningiomas

Advanced Meningioma Imaging

Noninvasive imaging methods are used to accurately diagnose meningiomas and track their growth and location. These techniques, including computed tomography, MRI, and nuclear medicine, are also being used to gather more information about the biology of the tumors and potentially predict their grade and impact on prognosis. In this article, we will discuss the current and developing uses of these imaging techniques including additional analysis using radiomics in the diagnosis and treatment of meningiomas, including treatment planning and prediction of tumor behavior.

Radiotherapy and radiosurgery for meningiomas

Meningiomas comprise a histologically and clinically diverse set of tumors arising from the meningothelial lining of the central nervous system. In the past decade, remarkable progress has been made in deciphering the biology of these common neoplasms. Nevertheless, effective systemic or molecular therapies for meningiomas remain elusive and are active areas of preclinical and clinical investigation. Thus, standard treatment modalities for meningiomas are limited to maximal safe resection, radiotherapy, or radiosurgery. This review examines the history, clinical rationale, and future directions of radiotherapy and radiosurgery as integral and effective treatments for meningiomas.

Malignant intracranial solitary fibrous tumor: A case report and literature review

Solitary fibrous tumor (SFT), previously termed hemangiopericytoma, is a rare primary intracranial tumor. SFT is classified into grades I, II, and III with different prognoses; grade III tumor has malignant characteristics with a high probability of recurrence and extracranial metastasis. We report the case of a 63-year-old female patient admitted to the Vietnam National Cancer Hospital with headache, dizziness, nausea, ataxia, and loss of balance. Computed tomography showed a markedly enhanced tumor, without calcification, located in the posterior fossa close to the tentorium cerebelli. No changes in the adjacent bone were seen. Magnetic resonance imaging revealed a lobular extra-axial tumor with prominent flow voids, a finding that has been seen frequently in these tumors. The tumor was resected following an initial diagnosis of SFT. Postoperative histology indicated a grade III SFT according to the World Health Organization 2021 classification. SFT is often misdiagnosed as meningioma, as they have some imaging features in common. However, we believe that there are some characteristic magnetic resonance imaging features that help to distinguish between these tumors, as well as playing an essential role in SFT grading and potentially guiding the best therapeutic decision.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Imaging and diagnostic advances for intracranial meningiomas

The archetypal imaging characteristics of meningiomas are among the most stereotypic of all central nervous system (CNS) tumors. In the era of plain film and ventriculography, imaging was only performed if a mass was suspected, and their results were more suggestive than definitive. Following more than a century of technological development, we can now rely on imaging to non-invasively diagnose meningioma with great confidence and precisely delineate the locations of these tumors relative to their surrounding structures to inform treatment planning. Asymptomatic meningiomas may be identified and their growth monitored over time; moreover, imaging routinely serves as an essential tool to survey tumor burden at various stages during the course of treatment, thereby providing guidance on their effectiveness or the need for further intervention. Modern radiological techniques are expanding the power of imaging from tumor detection and monitoring to include extraction of biologic information from advanced analysis of radiological parameters. These contemporary approaches have led to promising attempts to predict tumor grade and, in turn, contribute prognostic data. In this supplement article, we review important current and future aspects of imaging in the diagnosis and management of meningioma, including conventional and advanced imaging techniques using CT, MRI, and nuclear medicine.

Microcystic Meningiomas: MRI-Pathologic Correlation

BACKGROUND AND PURPOSE

Microcystic meningiomas (MM) are a distinctive, rare subtype of Grade I meningiomas with limited radiological descriptions. We intend to identify unique imaging phenotypes and seek radiopathological correlations.

METHODS

Retrospective analysis of histopathologically proven MM was undertaken. Clinicodemographic profiles, imaging, and histopathological characteristics were recorded. Spearman rank correlations among radiological and pathological attributes were performed.

RESULTS

Twenty-eight cases were analyzed (mean age = 45.5 years; M:F = 1:1.54; mean volume = 50.1 mL; supratentorial n = 27). Most lesions were markedly T2 hyperintense (higher than peritumoral brain edema-a unique finding) (89.3%) and showed invariable diffusion restriction, severe peritumoral brain edema (edema index >2 in 64.3%), a "storiform" pattern on T2-weighted images (T2WI) (75%), reticular pattern on postcontrast T1 (78.6%)/diffusion-weighted images (DWI) (65.4%), hyperperfusion, T1 hypointensity (84.6%), and absence of blooming on susceptibility-weighted image (80.9%). Storiform/reticular morphology correlated with large cysts on histopathology (ρ = .56; P = .005753).  Lesion dimension positively correlated with reticular morphology on imaging (ρ = .59; P = .001173), higher flow voids (ρ = .65; P = .00027), and greater microcystic changes on histopathology (ρ = .51; P = .006778). Peritumoral brain edema was higher for lesions demonstrating greater angiomatous component (ρ = .46; P = .014451).

CONCLUSIONS

We have elucidated varied neuroimaging features and highlighted pathological substrates of crucial imaging findings of MM. MM ought to be considered as an imaging possibility in an extra-axial lesion with a marked hypodensity on noncontrast computed tomography, markedly T2-hyperintense/T1-hypointense signal, and a storiform/reticular pattern on T2W/GdT1w//DWI.

Stereotactic Radiotherapy for Parasagittal and Parafalcine Meningiomas: Patient Selection and Special Considerations

Treatment options for intracranial meningiomas are surgical resection alone, surgery followed by adjuvant radiation therapy (RT), or exclusive RT. Parasagittal and parafalcine meningiomas are a subgroup of meningeal disease located close to the vascular structures. Considering the frequent venous invasion, a complete resection is not possible in the majority of cases, and even if a Simpson Grade I resection can be performed, the risk of recurrence is relevant. To date, few studies are focused on parasagittal and parafalcine meningiomas. Because of their specific related issues, particular considerations on decision-making process, outcome, and toxicity follow-up are mandatory. In fact, parasagittal and parafalcine meningiomas require a clear-cut radiological assessment, as well as a tailored toxicity risk evaluation. Moreover, similarly to other meningioma sites, also for parasagittal and parafalcine ones, a standardization of local control, toxicity, and quality of life evaluation is needed in order to lead to a pooled analysis of the results. In this context, our aim was to review the literature data regarding the role of both single-session and multisession radiosurgery (RS), and stereotactic radiotherapy (SRT) for parasagittal and parafalcine meningioma management, summarizing available data on safety and efficacy. It was also discussed how RS and SRT can be performed in a setting of evolving views concerning the treatment paradigm of the parasagittal and parafalcine meningiomas.

Metastatic meningioma: Case report of a WHO grade I meningioma with liver metastases and review of the literature

Meningioma represents the most frequently diagnosed primary brain tumor, accounting for over one-third of central nervous system neoplasms. The majority of tumors are categorized as benign. However, albeit rarely, meningiomas may metastasize to distant sites. We describe a 78-year-old man with a history of recurrent World Health Organization grade I meningioma managed who presented for evaluation of weakness and urinary retention. A computed tomography scan obtained in the emergency department revealed multiple scattered low-density liver lesions. Subsequent magnetic resonance imaging showed a 5.5-centimeter heterogeneous enhancing mass with 2 smaller enhancing lesions suspicious for a primary or secondary malignant neoplasm. Microscopic examination of a tissue sample obtained via liver biopsy demonstrated a metastatic spindle cell neoplasm with histologic features compatible with a diagnosis of World Health Organization grade I transitional meningioma. The patient was referred to hematology/oncology for systemic therapy.

Orbital malignant meningioma: a unique presentation of a rare entity

An elderly female with progressive proptosis was found to have an aggressive retrobulbar solid orbital mass. The mass was distinct from the optic nerve sheath and intracranial meninges, and produced concave erosion of the sphenoid wing. Operative findings demonstrated an orbital mass adherent to the dura of the superior orbital fissure. The mass did not demonstrate meningeal violation, infiltrate the superior orbital fissure, or display intracranial spread. The dura remained intact after gross total resection. Histopathology revealed a malignant meningioma with papillary and focal rhabdoid morphology and bony invasion (WHO grade III). The patient received 2500cGy of stereotactic radiotherapy in addition to gross total resection. Postoperatively, the signs and symptoms of orbital mass effect resolved (proptosis, relative afferent papillary defect, and periorbital edema) and the vision improved. There was no orbital recurrence or intracranial extension. The follow-up time was limited to eight months secondary to the patient succumbing to metastatic lung adenocarcinoma, which was demonstrated to be a separate process from the orbital meningioma. We propose the etiology of this tumor to be most consistent with an orbital malignant primary extradural meningioma - the first case reported in the literature.

Pediatric intracranial clear cell meningioma: a clinicopathological study of seven cases and literature review

BACKGROUND

In this study, we reported seven cases of pediatric intracranial clear cell meningiomas (CCMs) in our institution and reviewed the relevant literature to investigate the clinicopathological characteristics, treatment options, and prognosis of these rare tumors.

METHODS

From January 2005 to June 2016, we retrospectively reviewed seven pediatric intracranial CCMs in terms of their clinical data, preoperative MRI features, and prognosis. Moreover, a critical review of the English language literature was also conducted.

RESULTS

The patients consisted of two males and five females with a median age of 10.5 years (range 6-15 years) at initial surgery. Petroclival and cerebellopontine angle area was the most common location site (5/7). Accordingly, the most common initial manifestation was hearing loss (3/7), and the mean interval from onset of symptoms to admission was 6.8 months (1.5-24 months). Gross total resection was achieved in five patients. Of the six tumors with immunohistochemical records, MIB-1 labeling index varied from 3 to 20 % (mean 8.1 %). During the follow-up period (mean 76.9 months, range 16-180 months), four patients had experienced tumor recurrences and three patients died due to recurrences.

CONCLUSIONS

Pediatric intracranial CCMs have a tendency to recur. There is a significant relationship between MIB-1 labeling index and recurrence. Gross total resection is recommended; if not available, adjuvant radiotherapy should be used to reduce the recurrent rate. In addition, postoperative MRI follow-up should be monitored at an interval time after resection.

Radiologic and histologic features of the T2 hyperintensity rim of meningiomas on magnetic resonance images

A hyperintensity rim is often seen at the brain-tumor interface of meningiomas upon T2-weighted (T2WI) magnetic resonance imaging (MRI), and it is referred to as the cerebrospinal fluid (CSF) space; however, the true nature of the rim remains unclear. We surveyed the MRI findings and the histopathologic characteristics of such rims. Our study population consisted of 53 consecutive patients who underwent meningioma removal at our hospital. The intensity of the rim on MRI scans obtained with different imaging sequences was assessed in all patients. We used 22 tumors for histopathologic investigation: tissue samples were acquired from both the tumor surface and from a deep intratumoral site. Of the 53 meningiomas, 37 (69.8%) manifested a hyperintensity rim on T2WI (T2-rim). The other 16 showed neither a hyperintense nor a hypointense rim on their T2WI. An enhancement effect corresponding to the rim was observed in 28 of the 37 (75.7%) T2-rim positive tumors. While 9 among the 37 tumors with a T2-rim (24.3%) did not show rim enhancement, they showed low intensity on fluid-attenuated inversion recovery (FLAIR) images. The microvascular density in the tumor capsule was significantly greater in the 12 T2-rim and rim enhancement positive tumors than in 10 tumors that were T2-rim negative or T2-rim positive, but rim enhancement-negative ( p < 0.001, Mann-Whitney U test). We found that 75.7% of T2 hyperintense rims that were detected at the brain-meningioma interface reflected a microvascular-rich capsule layer, rather than the CSF space.

Lipomatous meningioma: Case report and review of the literature

Lipomatous meningiomas are a very rare form of brain meningiomas consisting of fat accumulation within the tumor. Magnetic resonance imaging (MRI) or computerized tomographic (CT) imaging can be utilized to visualize the fat accumulations, but histopathologic staining is necessary in order to make a definitive diagnosis. The key histopathologic feature is the identification of adipocyte-like cells within the tumor, but other markers have also been identified. In this case report and review of the literature, we discuss how to recognize the symptoms associated with lipomatous meningiomas and the definitive treatment approach for these rare tumors.