MRI findings of atypical meningioma with microcystic changes

Excerpt

A 54-year-old woman presented with visual disturbance and consulted with a physician at our hospital. Neurological examination revealed left hemianopsia. MRI of the brain revealed an extraaxial tumor with a markedly low T1 signal and a markedly high T2 signal in the right occipital region (Figs. 1a, 1b). Peritumoral edema was visible on the T2-weighted images (Fig. 1b). Contrast-enhanced T1-weighted images showed inhomogeneous and less intense enhancement (Fig. 1c). Diffusion-weighted imaging (DWI) was performed and an apparent diffusion coefficient (ADC) map (Fig. 1d) revealed much higher diffusion of the tumor (1.41 × 10⁻³ mm²/s) than normal white matter (0.70 × 10⁻³ mm²/s), equivalent to that of adjacent peritumoral edema (1.40 × 10⁻³ mm²/s). A diagnosis of microcystic meningioma was considered. Subsequently, the patient underwent total tumor resection. Intraoperatively, the tumor attached to the dura matter was soft and moist, resembling a jellyfish. No invasion into adjacent brain parenchyma was apparent.

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