Urothelial Carcinoma : Vascular Invasion
High-grade urothelial carcinoma within vessels in perivesical fat in a radical cystectomy specimen. For unequivocal vascular invasion, the tumor nests should be attached to the vessel wall and conform to its shape. Red blood cells, thrombus, or inflammatory cells are usually admixed with the tumor. Immunostaining with factor VIII or CD31 can be used to highlight endothelium when it is not evident on H&E stains.