Brain Tumour Imaging — Practice

A 34-year-old woman presents with chronic headache and visual disturbance. Contrast-enhanced MRI of the brain shows a well-defined, homogeneously enhancing extra-axial mass along the right sphenoid wing, with a broad dural base, a thin enhancing rim of dura tapering away from the mass on either side, and underlying hyperostosis of the adjacent bone. Which classic imaging sign best describes this appearance?