Association of Peritumoral Brain Edema on Preoperative MRI with WHO Histological Grade of Intracranial Meningioma: A Prospective Observational Study, Bangladesh

Background: Intracranial meningioma is considered to be the most frequently observed primary extra-axial tumor of the brain. This tumor constitutes one-third of total primary intracranial tumors. Despite being predominantly histologically benign, a large number of meningiomas exhibit aggressive changes. Peritumoral brain edema (PTBE) observed in meningiomas has been considered a potential contributor to intracranial pressure. Invasive properties of meningiomas with vascular permeability and pial invasion along with vascular endothelial growth factors may lead to this condition. Preoperative Magnetic Resonance Imaging studies are extremely important for assessment of potential changes in meningioma. But available studies concerning this association in a population of South Asian individuals are scarce. Methods: This prospective cross-sectional observational study was conducted in the Department of Radiology and Imaging in collaboration with the Department of Neurosurgery at the National Institute of Neurosciences & Hospital (NINS&H), Dhaka, Bangladesh, from June 2023 to May 2024. A total of 40 patients with radiologically suspected intracranial meningioma were enrolled using a purposive sampling technique. All patients underwent preoperative magnetic resonance imaging (MRI) of the brain followed by surgical excision and postoperative histopathological confirmation with WHO grading. Results: Peritumoral edema and its volume increased significantly with higher WHO grades (P = 0.001, P = 0.002), indicating greater tumor aggressiveness. Tumor size showed no significant variation (P = 0.296). Central necrosis correlated significantly with grade (P = 0.011), being most frequent in Grade II tumors (22.5%) Univariate logistic regression showed that male sex, irregular margins, peritumoral edema, central necrosis, and pial invasion were significant predictors of higher-grade meningiomas, while tumor size and heterogeneous enhancement were not. Most tumors measured >6 cm, followed by 3–6 cm, with smaller lesions being least common. Conclusions: Peritumoral brain edema and the presence of aggressive magnetic resonance imaging characteristics such as irregular margins, necrosis, and pial infiltration were strongly predictive of higher grades of meningioma classified according to the WHO grading system. Purely size-based prediction of grades was impossible based on the results of the present study.