Dural-based large B-cell lymphoma masquerading as a tentorial meningioma.

A 53-year-old woman presented with a 2-week history of headache and vertigo. Computed tomography revealed a hyperdense tumor, measuring 30 × 31 × 36 mm in diameter, in the anteromedial parts of the cerebellar hemispheres. Cerebral magnetic resonance imaging 10 days later revealed an apparent extra-axial tumor with broad attachment to the medial tentorium cerebelli and rapid growth to a diameter of 40 × 41 × 46 mm. Cerebral angiography revealed no obvious feeding vessels or tumor stains. The patient underwent biopsy through the left occipital transtentorial route. The histological appearance was consistent with diffuse large B-cell lymphoma. Intracranial lymphoma may present as a dural tumor that mimics a meningioma. Rapid tumor growth incongruous with benign meningiomas should be assumed to be possible lymphoma, and prompt biopsy should be performed.