Glomeruloid vascular structures in glioblastoma multiforme: an immunohistochemical and ultrastructural study

摘要: Microvascular proliferation and glomeruloid vascular structures are important histopathological features of glioblastoma multiforme (GBM). The nature cells participating in the formation these remains unclear is subject this study. To define better, immunohistochemical markers directed against Factor VIII-related antigen (FVIIIR:Ag), alpha smooth-muscle actin (alpha-SMA), lectin Ulex europaeus agglutinin type I (UEA-I) were used. Cells lining channels a large number proliferating abluminal structure showed positive cytoplasmic staining for FVIIIR:Ag UEA-I. Abluminal luminal variably labeled alpha-SMA. Ultrastructurally, complex aggregates focally anastomosing capillaries with narrow lumina composed structure. Endothelial hyperplastic, varied size shape, overlapped focally, contained numerous filaments. Tight junctions bound together adjacent overlapping endothelial cells. Weibel-Palade bodies, usually absent from brain microvessels, present increased numbers newly formed capillaries. Each capillary loop was surrounded by basal lamina encompassing discontinuous layer pericytes. This study indicates that GBM microchannels lined hyperplastic have an altered morphological phenotype supported pericytes devoid astrocytic end-feet.