Dural metastases mimicking meningioma. Case report and review of the literature.

The typical appearance of meningioma on CT and MRI is well known. Particularly in the elderly, the imaging appearance is sometimes considered diagnostic of these benign tumours without histopathological confirmation. However, other more aggressive neoplasms can present with a classical CT and MRI appearance of meningioma, indicating the need for histopathological confirmation wherever possible. We report a case of dural metastases which, on both pre-operative CT and MRI and at surgery, had the typical appearance of a falcine meningioma. Histopathology and immunohistochemistry revealed adenocarcinoma of renal cell origin, and the renal primary was identified on subsequent abdominal investigation. The literature regarding dural metastases is reviewed. To our knowledge, this is the first reported case of a renal carcinoma metastasizing directly to the dura. Although rare, dural metastases can mimic meningioma, and this needs to be considered if conservative therapy or radiosurgery are to be offered to a patient with radiological diagnosis of meningioma.