This study was novel in that it compared both histochemical and immunohistochemical methods for identifying vascular invasion in cases of colorectal cancer in which vascular invasion had not been identified during initial reporting. Highlighting of endothelium significantly increases the observed incidence of vascular invasion in colorectal cancer compared with hematoxylin and eosin alone. Elastic van gieson seemed sensitive for the presence of vascular invasion but with uncertain specificity. The possibility that these immunohistochemical methods may identify a subset of patients with colorectal cancer who may benefit from chemotherapy warrants further study.