OUTLINE: All patients receive an injection of isosulfan blue into peritumor serosa upon intraoperative identification of the primary tumor, prior to mesenteric mobilization. If colonoscopy is otherwise indicated, the injection may be delivered to the peritumor mucosa via colonoscopy during the case. The mesentery adjacent to the injection is inspected and the lymphatic pattern and nodes demonstrated by the isosulfan blue are diagrammed and photographed. The sentinel node(s) are surgically dissected and evaluated. If needed, a second injection of isosulfan blue may be given. Prior to mobilization of liver for resection of metastases, isosulfan blue is injected subcapsularly around the metastatic lesion.