Different vascular patterns of medulloblastoma and supratentorial primitive neuroectodermal tumors

Astrocytoma vasculature patterns differ according to histological grade of malignancy with glioblastoma multiforme (WHO grade IV) showing most extensi ve endothelial proliferation. Here, we determined whether the vascular patt erns of medulloblastoma and supratentorial primitive neuroectodermal tumors (PNETs), which can be hardly distinguished histopathologically, differ. We evaluated the spatial organization of vessels in medulloblastomas and PNET s using antibodies to von Willebrand factor (VWF) and CD34. Medulloblastoma capillaries showed slight endothelial cell hyperplasia. Microvessels sprou ted from the capillaries and formed glomeruloid clusters. There were areas with chains of unopposed endothelial cells (3-10 cells). Supratentorial PNE Ts had highly branched capillaries with extensive endothelial cell hyperpla sia. Glomeruloid arrays of microvessels extended from the capillaries. Smal l fragments of endothelial tubes were scattered throughout the tumor. There fore, medulloblastomas and supratentorial PNETs showed different spatial or ganization of tumor vessels which can be used for differentiation of each t umor entity. These Vascular patterns may reflect different tumor derived an giogenic stimuli. (C) 1999 ISDN. Published by Elsevier Science Ltd. All rig hts reserved.