Meningiomas associated with peritumoural venous stasis: three types on cerebral angiogram.

Many factors have been suggested as possible mechanisms for the development of peritumoural oedema in meningioma. Venous compression by the tumor is thought to be one factor, but reports presenting a direct relationship between venous compression and the formation of oedema are rare. We have recently observed 6 meningioma patients in whom venous stasis contributed to peritumoural oedema. The stasis was due to 1) compression of an adjacent cortical vein by the tumour with stasis at the site of compression and/or its distal portion, 2) compression of adjacent brain by the tumour with prolonged perfusion and delayed venous return (visualized as pial staining in the capillary and venous phases), and 3) presence of an early draining vein linked to a nearby cortical vein with stasis at its periphery. Venous compression and stasis seem to be related not only to the formation of peritumoral oedema but also to the occurrence of haemorrhagic infarction after the resection of meningiomas.