Which features make haemangiopericytoma plausible to be considered?
Although impossible to be certainly separated from a meningioma on imaging, some features make haemangiopericytomas a differential to be included. In this case, in particular, the fact that the tumour goes through the falx instead of involving it on both faces.
Technique: Pre and post-contrast axial images were obtained through the brain, with posterior sagittal and coronal reformations.
Findings: There is a solid, well-defined, and extra-axial tumour involving the mid falx cerebri, which shows to be spontaneously hyperdense, with some minor peripheral calcifications foci, abutting over the adjacent frontal lobes and partially involving the superior sagittal sinus. The lesion express homogeneous and vivid contrast enhancement and cause mild surrounding oedema in the adjacent right superior frontal gyrus. It is clear that the lesion goes through the falx.
Remainder brain is unremarkable.
Conclusion: Solid extra-axial tumour involving the mid falx cerebri, which most likely represents a meningioma; Haemangiopericytoma is among the differential diagnosis. Further evaluation with MRI venography is advised to assess possible sinus invasion.