Anatomic location is a risk factor for atypical and malignant meningiomas

Abstract

Background Grade II and III meningiomas have higher rates of tumor recurrence than grade I meningiomas after surgery and/or external irradiation. As the utility of non-invasive treatments for brain tumors increases, it is becoming increasingly important to assess the likelihood that a tumor is not benign before treatment initiation. Hence, we have reviewed a large-series of our patients to determine risk-factors for higher-grade pathology with particular interest paid towards tumor location. Methods We reviewed 378 patients presenting to our institution from 2000 to 2007 with: histologically confirmed meningioma, central pathology grading according to the WHO 2000 guidelines, and tumor location confirmed with preoperative imaging. We performed univariate and multivariate logistic regression on potential risk-factors for high-grade pathology. Results Risk-factors for grade II/III pathology included non-skull base location (twofold) and male gender (two-fold). Patients with prior surgery had a three-fold increased incidence of higher-grade meningiomas at presentation to our center. We controlled for this referral bias by performing a multivariate regression, and analysis without patients receiving prior treatment. 97% of operations were performed for tumor size and clinical symptoms, while less than 3% for interval growth or features concerning of higher-grade pathology. Conclusion Non-skull-base meningiomas, male gender, and prior surgery impart increased risk for grade II or III pathology. This increased risk translates to probable poorer prognosis and increased likelihood of recurrence after treatment. Thus, it is prudent to take these specific variables into consideration in conjunction with the complete clinical presentation when advising patients regarding their prognosis.

Correlation between magnetic resonance imaging grading and pathological grading in meningioma

“…16,20,21,30 We also observed a similar finding in our study, that non-skull base meningiomas were more likely to be high-grade. Tumors locations are significantly different between patients with benign and those with high-grade meningiomas.…”

“…Male sex is reported to be associated with a higher risk of highgrade meningioma than female sex according to a few reports. 16,17 Although male sex was more likely to be a predictor of high-grade meningioma in our study (OR 1.83, 95% CI 0.77-4.36), there was not a statistically significant difference. Also, adding this variable did not improve the model's explanatory power.…”

“…Age, tumor-brain interface, tumor enhancement, brain edema, and tumor location were significantly different between patients with benign meningiomas and those with high-grade meningiomas. According to the results of multivariate logistic regression analysis, age ≥ 75 years, unclear tumor-brain interface, and heterogeneous tumor enhancement were strong independent predictive factors, with ORs of 4.28 (95% confidence interval [CI] 1.14-16.10; p = 0.0314), 16.55 (95% CI 2.23-122.85; p = 0.0061), and 4.39 (95% CI 1.26-15.33; p = 0.0204), respectively ( Table 2). There was a negative correlation between unclear tumor-brain interface and positive capsular enhancement (OR 0.1; p = 0.001, data not shown).…”

“…22,24 However, this statement is not supported by other studies. 13,16,17 This problem occurs because different years were used as the dividing line in different reports. In this study, we use different years as the dividing line including 65, 70, and 75 years old.…”

Magnetic Resonance Image Manifestations of the Atypical Meningioma

“…Differential diagnosis of atypical meningioma is difficult, mainly because the diversity of the site, as well as the borderline of imaging features increase the difficulty for the preoperative diagnosis (Kane et al, 2011). First of all, due to the characteristics of borderline lesion of atypical meningioma, lobules boundary in morphology, heterogeneity signal, cystic degeneration and the indirect signs of destruction of the around bone structure all suggest its developing characteristics (Kim et al, 2009).…”