Base MRI Imaging Characteristics of Meningioma Patients to Discuss the WHO Classification of Brain Invasion Otherwise Benign Meningiomas

Abstract

Purpose: Compared and analyzed the MRI imaging features of brain invasion otherwise benign (BIOB) meningiomas and WHO grade 1, grade 2 meningiomas, discussed the WHO grading of BIOB from the perspective of imaging.

Materials and methods: A retrospective analysis was performed on 675 meningiomas patients who carried on MRI examination from January 2006 to February 2022. Setting the 2022 Central nervous system (CNS) WHO Guidelines as the gold standard for pathological diagnosis. Statistical analysis of age, gender, and MRI features of meningiomas in relation to WHO grade and brain invasion.

Results: Among 675 cases meningiomas, 543 (80.4%) were WHO grade 1, 123 (18.2%) were WHO grade 2, and 9 (1.3%) were WHO grade 3. There were 108 cases meningiomas with brain invasion (BI) (16.0%) and 567 cases without BI (84.0%). Among BI cases, 67 cases were BIOB. Compared the MRI features between BIOB and WHO grade 1 meningiomas, multivariate analysis demonstrated that the most strongly factors associated with distinguish them were enhancement degree, peritumoral edema, tumor-brain interface, fingerlike protrusion, mushroom sign, and bone invasion (AUC: 0.925 (0.901∼0.945), sensitivity: 0.925, specificity: 0.801). Compared the MRI features between BIOB and WHO grade 2 meningiomas, multivariate analysis demonstrated that the most strongly factors associated with distinguish them were enhancement degree and the tumor-brain interface (AUC: 0.779 (0.686∼0.841), sensitivity: 0.746, specificity: 0.732), their efficacy was slightly weaker.

Conclusions: BIOB is more similar to WHO grade 2 meningiomas in clinical and imaging features than WHO grade 1, so we think that it may be reasonable to classify BIOB as WHO Grade 2 meningiomas in the guidelines.

Keywords: BIOB; Brain invasion; Magnetic Resonance Imaging (MRI); WHO grade.

Figure 1.

ROC curves of six independent risk factors for WHO grade 1 meningiomas compared with BIOB.

Figure 2.

ROC curves of total variables for the comparison of WHO grade 1 meningiomas and BIOB.

Figure 3.

ROC curves of two independent risk factors and total variables for WHO grade 2 meningiomas compared with BIOB.

Figure 4.

a. Axial T1-weighted sequence in a 38-year-old man with a 2-month history of Blurred vision with dizziness and vomiting, no-lobulated mass located in the parietal lobe, a well-circumscribed. b and e. Axial T2-weighted sequence and Coronal T2 – flair sequence showed the tumor is to be isointense to gray matter with massive peritumoral edema. c. T1WI enhancement sequence showed blurred tumor–brain interface. d. DWI signal of the lesion was not high. f. Pathological HE staining (20 × 10 magnification): the patient was diagnosed as transitional meningioma with brain invasion. The arrow shows the infiltrated brain tissue.