The authors present a case of huge intraventricular meningioma on the trigone of the right lateral ventricle of a 42-year old female. The mass was a huge multilobulated yellowish gray tumor, which was relatively rubbery hard. Intratumoral removal was performed by ultrasonic aspirator at east. Later thin outer surface of the tumor was retracted and extirpated. Microscopic examination revealed transitional type of meningioma consisted of concentric whorls of elongated tumor cells and psammoma bodies. Occasionally the center of whorls contained capillary blood vessels. Postoperative course was uneventful. Extremely minimal visual field defect was detected without the patient's subjective complaint.
Adult ; Blood Vessels ; Capillaries ; Female ; Humans ; Lateral Ventricles ; Meningioma ; Ultrasonics ; Visual Fields

The histopathologic findings of the intracranial meningima are variegated and those of magnetic resonance imaging (MRI) which has been used for preoperative evaluation are also varied in signal characteristics. In order to aid the preoperative diagnosis, authors analyzed MRI and microscopic findings in twenty eight meningioma cases which underwent surgery. The results were summarized as follows : 1) Meningothelial, fibrous and transitional subtypes showed isointense signal on T1-weighted image and iso and/or hyperintense signal T2-weighted and proton density images compared to the signal intensity of the gray matter. 2) Microcystic subtype was isointense signal on T1-weighted image and hyperintense signal on T2-weighted and proton density images. 3) Variation of signal intensity might be correlated to the ratio of the stroma in the tumor. 4) Peritumoral edema was not closely related to the pathologic subtypes or location of meningioma, but it seemed to be correlated with the size of tumor.
Diagnosis ; Edema ; Magnetic Resonance Imaging* ; Meningioma* ; Protons