A Case of Microscopic Tumor Embolism with Liver Metastasis of Colon Cancer Identified by Intraoperative Indocyanine Green Fluorescence

Abstract

A 64-year-old woman underwent follow-up CT after surgical treatment of sigmoid colon cancer, and a mass with a diameter of 10 mm was found in the S2 region of the liver and diagnosed as metastatic liver cancer. Laparoscopic partial resection of liver S2 was performed, and intraoperative indocyanine green (ICG) fluorescence also showed different fluorescent sites aside from the tumor, which was resected for diagnosis. On pathological examination, microscopic tumor embolism of adenocarcinoma was found in the bile duct inside Glisson's sheath, which was diagnosed as metastasis of sigmoid colon cancer. The patient's postoperative course was good, without any complications, and she was discharged on the 4th postoperative day.

Previous reports suggested that intraoperative ICG fluorescence is effective not only for the primary lesion, but also for metastatic liver cancer to identify the tumor. On the other hand, when the mass not recognized before surgery is fluorescent, its significance is controversial. In the present case, microscopic tumor embolism with liver metastasis of colon cancer, which could not be detected on preoperative examination, was identified by intraoperative ICG fluorescence. This case is reported along with a review of the relevant literature.