Rectum, Recto-sigmoid adenocarcinoma with large-vessel invasion, EVG stain

Colorectal adenocarcinoma is a common malignancy requiring pathologic evaluation for prognosis and staging. Section from a low anterior resection shows large vessel invasion by adenocarcinoma, and the vessel is highlighted by EVG stain (this slide). While significant inter-observer variability in their detection has been reported, large-vessel invasion is believed to carry an increased risk. While not part of the CAP protocol, large-vessel invasion warrants a separate comment. EVG stain nicely highlights the elastic tissue in this case, but trichrome stain can also be employed.