Primary intraosseous meningiomas of the skull.

The plain film, computed tomography (CT) and angiographic findings in 10 patients with primary intraosseous meningioma were reviewed and the differential diagnosis considered. In nine patients with benign primary intraosseous meningioma, the radiological findings revealed intraosseous expansile growth. In one patient with the malignant form of the tumour, osteolytic growth was evident on plain film and CT. In eight patients, the tumour tissue was hyperdense (65-85 HU) on the unenhanced CT images and striking enhancement was shown in seven. In five patients angiography showed that the external carotid artery fed the tumour, while in one the vasculature was normal. Benign primary intraosseous meningioma showed expansile growth and malignant tumour showed osteolytic growth. If a combination of the plain film, angiogram and CT findings is considered, a diagnosis of the benign tumour can be made and a diagnosis of benign meningioma can be suggested.