The Pathogenetic Mechanisms of intratumoral hemorrhage in meningioma: The role of microvascular differentiation

The transformation of normal cells into neoplastic cells is based on a series of gradual and progressive processes . One of the most important aspects underlying the tumorigenesis ist hat neoplastic proliferation needs mechanisms to ensure cancer development, bypass the body's protective strategies, and survive the apoptotic mechanisms. Subsequently, measures to promote replicative immortality and vascular support will be required. If cancer develops in an area offering excellent vascularization, pre-existing vascular circuits can supporti ts growth .Otherwise,tumor angiogenetic mechanisms will trigger new vascular networks, which will be necessary for tumor survival and expansion. The latter occurrence is what takes place in most of the neoplasms characterized by high growth pattern: proangiogenic factors secreted by the tumor, the most important being the vascular endothelial growth factor (VEGF), create a chemotactic gradient able to recruit endothelial cells and pericytes from the existing vascular system .