====== Cystic anaplastic astrocytoma ======

Cyst formation is common in [[pilocytic astrocytoma]]s but rare in [[anaplastic astrocytoma]].

It has been reported that tumor-related angiogenesis and microvascular extravasation due to blood-brain barrier (BBB) disruption are the driving forces of cyst formation 
((Strugar JG, Criscuolo GR, Rothbart D, Harrington WN. Vascular endothelial growth/permeability factor expression in human glioma specimens: Correlation with vasogenic brain edema and tumor-associated cysts. J Neurosurg. 1995;83:682–689. doi: 10.3171/jns.1995.83.4.0682.))
((Lohle PN, van Mameren H, Zwinderman KH, Teepen HL, Go KG, Wilmink JT. On the pathogenesis of brain tumour cysts: A volumetric study of tumour, oedema and cyst. Neuroradiology. 2000;42:639–642. doi: 10.1007/s002340000363.))
((Weindel K, Moringlane JR, Marmé D, Weich HA. Detection and quantification of vascular endothelial growth factor/vascular permeability factor in brain tumor tissue and cyst fluid: The key to angiogenesis? Neurosurgery. 1994;35:439–449. doi: 10.1097/00006123-199409000-00012.))