Intraventricular meningiomas: radiological findings and clinical features in 12 patients

To characterize the computed tomography (CT) and magnetic resonance (MR) imaging findings and clinical features of intraventricular (IV) meningiomas.

CT (n=8) and MR (n=12) images and medical records of 12 patients (five men and seven women; mean age, 36 years; range, 14-68 years) with pathologically proven IV meningiomas were retrospectively reviewed. Particular attention was put on the size and shape of the mass; internal architecture such as necrosis or calcification within the tumor; peritumoral edema; associated hydrocephalus and clinical features such as symptoms, treatment, and prognosis.

There were five of benign, three of atypical, and four of malignant subtype. All lesions were located in the lateral ventricle ranging in maximum diameters from 4.0 to 7.3 cm (mean, 5.4 cm). All tumors had lobulated shape. Five (71%, 5/7) of the atypical and malignant IV meningiomas, but just two (40%, 2/5) benign IV meningiomas, had irregular lobulation. The tumors were isointense (n=7) or hypointense (n=5) to gray matter on T1-weighted images, whereas isointense (n=9) or hyperintense (n=3) on T2-weighted images. On gadolinium-enhanced T1-weighted images, homogeneous enhancement was seen in five lesions, and heterogeneous enhancement was seen in seven lesions, Most patients (n=10) had associated localized hydrocephalus due to ventricular entrapment. Intratumoral necrosis was seen in two cases (17%, 2/12), all of these were malignant subtype. In two cases of atypical and malignant subtypes, recurrences were found during the follow-up period after surgical resection.

More than half (n=7, 58%) of the IV meningiomas were of atypical (n=3) or malignant (n=4) subtype. IV meningiomas tend to have a lobulated shape, especially irregular lobulation, and intratumoral necrosis was frequently seen in the atypical or malignant subtypes.