Uncommon and atypical meningiomas and imaging variants: A report of 7 cases

Related mechanisms, current treatments, and new perspectives in meningioma

Meningiomas are non-glial tumors that are the most common primary brain tumors in adults. Although meningioma can possibly be cured with surgical excision, variations in atypical/anaplastic meningioma have a high recurrence rate and a poor prognosis. As a result, it is critical to develop novel therapeutic options for high-grade meningiomas. This review highlights the current histology of meningiomas, prevalent genetic and molecular changes, and the most extensively researched signaling pathways and therapies in meningiomas. It also reviews current clinical studies and novel meningioma treatments, including immunotherapy, microRNAs, cancer stem cell methods, and targeted interventions within the glycolysis pathway. Through the examination of the complex landscape of meningioma biology and the highlighting of promising therapeutic pathways, this review opens the way for future research efforts aimed at improving patient outcomes in this prevalent intracranial tumor entity.

Clinicopathological characteristics and prognostic factors of atypical meningiomas with bone invasion: a retrospective analysis of nine cases and literature review

BACKGROUND

Meningiomas are the most common primary neoplasms of the central nervous system in adults, arising from the arachnoid cap cells. Thus, grade 2 meningiomas are situated on the border between benignity and malignancy. Among the many prognostic factors that have been investigated in these tumors, bone invasion is one of them.

OBJECTIVE

The aim of our study was to identify whether bone invasion influences tumor recurrence and progression-free survival (PFS) in patients with atypical meningiomas (AMs).

PATIENTS, MATERIALS AND METHODS

Out of 81 patients with AMs followed over a period of five years, we identified nine patients with bone invasion. We analyzed their demographic, clinical, imaging, and pathological characteristics, such as age, gender, radiological aspects, morphological features, extent of resection, recurrence rate, and PFS over a follow-up period of 60 months. Bone invasion was determined based on preoperative, surgical, and pathological reports.

RESULTS

Out of the nine patients with bone invasion, four had convexity meningiomas, four had parasagittal meningiomas and one had a falcine meningioma. Regarding tumor recurrence∕progression, most patients (n=6) recurred within the first 24 months after surgery. Our study showed that the early recurrence/progression of tumor (at 12 months) correlated with extensive presence of malignancy criteria, especially with the presence of 15-18 mitoses∕10 high-power fields, as well as with large foci of spontaneous necrosis, but also with tumor bone infiltration, extensive bone lamellae destruction, and tumor infiltration of adjacent muscle with its atrophy due to tumor compression. Patients with bone invasion had a PFS of 29.3 months, compared to patients without invasion who had a higher PFS (49.3 months). Significant statistical associations were observed between bone invasion and tumor recurrence (p=0.002) and PFS (p=0.004).

CONCLUSIONS

Our study emphasizes the importance of a thorough histopathological examination of the surgical specimen, which can provide significant data for the assessment of the progression of an AM [World Health Organization (WHO) grade 2] with bone invasion. AM infiltration in adjacent bone and muscle increases the rate of tumor recurrence and decreases PFS over a follow-up period of 60 months.

Factors related to morbidity and mortality of meningiomas resection‑associated venous thromboembolism (Review)

Patients undergoing intracranial meningioma removal have been reported to have an increased risk of venous thromboembolism (VTE). The present study aimed to study meningioma operations and ascertain rates of postoperative VTE more closely and to find out the associated parameters with VTE-related morbidity and mortality in meningioma patients following resection. This meta-analysis included articles involving meningiomas surgery and postoperative VTE [thromboembolic complications: deep venous thrombosis (DVT) and pulmonary embolism (PE)] published in full-text form between January 1980 and January 2021). Collected variables included: First author name, study period covered, publication year, total number of patients and age, number of males, surgical duration, body mass index (BMI), tumor location, proliferation marker for human tumor cells Ki-67 and VTE-related morbidity and mortality. After the initial search and applying all exclusion and inclusion criteria, five articles were left in the final article pool. The total number of patients was 6,505 who underwent surgery for meningiomas and 299 (4.5%) revealed postoperative VTE. The final results showed no potentially significant difference between the total sample and the postoperative VTE group in tumor location and proliferation marker Ki-67 for human cells. By contrast, the results of the analysis for surgical duration and BMI showed a statistically significant difference. Patients who had experienced open surgery for meningiomas were associated with postoperative VTE. Furthermore, surgical duration and BMI were statistically significant VTE-related parameters in patients who underwent meningioma surgery, showing an association with VTE-related morbidity and mortality.