Presentation
One-month history of headache and intermittent memory loss.
Patient Data
There is a heterogenous enhancing mass with a significant cystic component in the left frontal lobe. Mass effect with the underlying gray matter and lateral ventricle compressed and sulcal effaced. Subfalcine herniation to the right with associated left uncal herniation. The presence of vasogenic edema is most likely due to a combination of local invasion as well as the severity of the mass effect.
There is restricted diffusion in the solid component. The cystic component is intermediate signal on T1, high signal on T2, high signal on FLAIR sequence and does not follow CSF signal. This may represent evolving blood products from a previous bleed or proteinaceous material.
Conclusion: Extra-axial mass with likely gray matter invasion adjacent to the left frontal lobe. The extra-axial location of the mass and its diffusion restriction is consistent with a meningioma, however, the imaging characteristic and large cystic component is atypical. This may possibly due to an underlying arachnoid cyst at the area described.
Case Discussion
This patient underwent a resection of the left frontal lobe lesion.
Histology
The sections show a meningothelial meningioma with areas of microcystic change. Some geographic necrosis is seen. The mitotic count is up to 8 mitoses per 10 high power fields. Nucleoli are prominent. There is no sheet-like growth. Brain invasion is not identified.
FINAL DIAGNOSIS: Atypical meningioma (WHO grade II)