What MRI feature is most characteristic of a meningioma?

• A. Extra-axial, well-circumscribed lesion with a dural tail enhancement pattern.
• B. Intra-axial lesion with infiltrative borders.
• C. Ring-enhancing lesion with brain abscess-like appearance.
• D. Calcified lesion without dural tail.

Answer: (A)

The feature that best identifies a meningioma on MRI is its extra-axial, dural-based appearance with vivid enhancement along the dura, often described as a dural tail sign. This reflects that the tumor arises from the meninges and sits outside the brain tissue, typically displacing the adjacent brain rather than invading it. The lesion is usually well circumscribed and enhances strongly with contrast, which helps distinguish it from intra-axial tumors that arise within the brain parenchyma and tend to have infiltrative borders. Calcifications and skull hyperostosis can accompany meningiomas, supporting the diagnosis, while other patterns—such as a ring-enhancing lesion with central necrosis (which suggests abscess or a necrotic tumor) or an intra-axial infiltrative lesion (typical of gliomas)—are less characteristic for a meningioma.