Do aggressive imaging features correlate with advanced histopathological grade in meningiomas?

Atypical and malignant meningiomas are more likely to recur than benign meningiomas. We aimed to distinguish atypical and malignant meningiomas from benign meningiomas based on imaging findings. Between 2004 and 2007, a total of 75 patients with resected intracranial meningiomas were retrospectively reviewed. Histopathological grades were assigned as benign and atypical/malignant meningiomas according to the World Health Organization (WHO) classification. All patients received preoperative CT scans and MRI studies. Six aggressive imaging features were evaluated and compared between the two groups: (i) intratumoral cystic change; (ii) hyperostosis of the adjacent skull; (iii) bony destruction; (iv) extracranial tumor extension through the skull base foramina; (v) arterial encasement; and (vi) peritumoral brain edema. There were 59 benign and 16 atypical/malignant meningiomas. Only intratumoral cystic change and extracranial tumor extension through the skull base foramina were more prevalent in atypical/malignant meningiomas (p=0.001). Hence, these two imaging features might be potential markers of atypical/malignant meningiomas.