Peritumoral subarachnoid hemorrhage in microsurgical transitional interface type meningioma: may the interface play a role?

The evidence of an intracranial hemorrhage from a meningioma, in comparison with bleeding from different intracranial tumours, is very infrequent. The pathophysiological mechanisms that can explain the possibility of bleeding from meningiomas have not been yet completely clarified. We report a case of a left parasagittal meningotheliomatous meningioma, situated in the premotor cortex, presenting with a peritumoral hemorrhage, at the interface between the meningioma and the brain parenchyma, and strictly confined within the subarachnoid space. A detailed immunohystochemical study of the tumour was performed. The neuroradiological and neurosurgical analysis of the tumour-to-brain interface, served to understand the pathophysiology of this uncommon behaviour. Other possible pathomechanisms explaining bleeding from meningiomas, in the light of the more recent literature are discussed.