Intraoperative indocyanine green imaging facilitates optimal surgical margin for colorectal liver metastasis with preoperatively undetected intrabiliary tumor growth.

Highlight Colorectal liver metastases readily invade the bile ducts, but diagnosis of intrabiliary tumor growth remains difficult despite the development of radiological techniques. In the present case, Seo and colleagues demonstrate how intrabiliary tumor growth which was not observed on preoperative images was clearly visualized on indocyanine green fluorescence imaging.