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We cannot talk about radiological aspects of this most frequent intracranial tumor, which is mostly benign, fortunately – aside from some exceptional cases – without mentioning its clinical signs, otherwise it would be less understandable that a smaller meningeoma is found as an incidental finding on the course of a CT or MRI scan. Being a benign and slowly growing, extraaxial tumor type, it is characterized by a prolonged course and poor symptomology. Sometimes headache is the awareness-raising sign, but epileptic seizures, motor deficits, sensuous sensations can be also present. Given on its localisation, exophthalmus can also develop.
Complications can develop if the tumor grows extremely large or due to its localisation as well. A very severe complication is if the tumor overgrows in the adjacent sinus (MRA demonstrates it exquisitely) causing a secondary thrombosis there as well, however, stenosis and thrombosis of the arteries can be also generated as well as the compression of cerebral nerves.
Due to its slow course symptoms are generated in middle age subjects.
Localisation: Characteristic localisations include falx, tentorium, convexity, lesser wing of sphenoid bone and tuberculum sellae, because they stem from the meninges. Meningeoma is often solitary, but multiple appearence is also possible. As a remark, it has been observed that meningeomas can develop in the irradiated area due to skull /cerebral radiation therapy (e.g. trichophytosis formerly, or nowadays e.g. because of pituitary tumor) further on (especially in case of low dose irradiation).
Radiology: In general, both imaging methods (CT, MRI) demonstrates a characteristically sharp-edged structure often surrounded by a perifocal edema. Perifocal edema is unnecessarily accompanied which might lead to misinterpretation. Presumably, peritumoral edema can refer to the malignity of meningeoma, even as this phenomenon can be associated with neoangiogenesis and microvascular proliferation (VEGF expression) in case of other tumors generating large vasogenic edema. It is considered as an attribution of meningeomas with recurrent liability. „Cystic” parts can stem from older hemorrhage or can be considered as a liquor inclusion as well.
The chapter structure
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