Cystic meningioma

Abstract

Cystic meningioma is an uncommon form of meningioma and the radiological appearance and location of the cystic/solid components of the mass may create a diagnostic dilemma. We report on the case of an 80-year-old left-handed man who presented with recurrent focal motor seizures and secondary generalisation. A large left-sided parieto-occipital cystic mass was detected on contrast CT of the brain. The appearance suggested a malignant tumour. However, brain MRI with gadolinium delineated the solid and cystic component precisely. A provisional diagnosis of cystic meningioma was made and this was confirmed histologically after resecting the tumour surgically. It was a benign WHO Grade I fibroblastic meningioma. The preoperative diagnosis of cystic meningioma is not that straightforward. Brain MRI with gadolinium has a better diagnostic yield than CT scanning. Histopathological examination of the tumour cells should always be performed to confirm the category and subtype of the tumour.

Figure 1

Contrast CT of the brain of the patient. There is a large left-parieto-occipital contrast-enhanced mass surrounded by hypodense rim and perilesional oedema. There is compression of the adjacent lateral ventricle. The radiologist suggested a diagnosis of primary or secondary malignant tumour.

Figure 2

MRI of the patient with different sequences; axial T1-weighted film with gadolinium (A), coronal T2-weighted film (B), axial T2-FLAIR film (C) and axial diffusion-weighted image (DWI) film (D). There is a well-defined extra-axial durally based mass measuring 6.6×5.1×65 cm in maximum diameters. The mass is located at the left parieto-occipital region, and consists of solid and peripheral cystic components. The solid component shows intermediate signal intensities on the T1-weighted and T2-weighted images with restricted diffusion on the DWI and demonstrates homogenous contrast enhancement. The mass shows no underlying cerebral invasion but there is perilesional brain oedema and mass effect on the adjacent brain tissue and left lateral ventricle. This is cystic meningioma.