Intraventricular malignant meningioma: one case report.

We report a case of primary intraventricular malignant meningioma in a 74-year-old man who presented with progressive weakness of the left limbs and dizziness, The preoperative magnetic resonance (MR) imaging of the head initially suggested that a glioblastoma multiforme or a metastatic lesion might be present. But later, the excised tumor was histologically diagnosed as a primary malignant meningioma. So far, only a few cases of intraventricular malignant meningioma have been reported. The MR imaging of this tumor has rarely been described in the literature. In the present case, the mass lesion showed hyperintensity on the T1-weighted image (T1WI) and hypointensity on the T2-weighted image (T2WI) which was not commonly seen in meningioma. The unusual MR imaging of this case may be attributed to the intratumoral hemorrhage. Although intraventricular malignant meningioma is difficult to diagnose based on MR or computed tomographic images alone, the characteristics of the MR images in the present case may offer an option for preoperative differential diagnosis of intraventricular tumors.