Unexpected detection of a submillimeter early hepatocellular carcinoma focus by intraoperative near-infrared fluorescence imaging-a case report

Background: Prognosis of hepatocellular carcinoma (HCC) is closely related to residual tumor cells and tissues after tumor resection. Thus, close monitoring to ensure complete removal of residual tumor is fundamental. In this regard, intraoperative near-infrared fluorescence (NIRF) imaging has been of great assistance to surgeons for precision cancer surgeries. However, up to now, the identification of tiny lesions has not been reported. Herein, we report our findings on the case of an ultra-small HCC focus of about 430 mu m that was successfully detected using NIRF during real-time monitored liver cancer surgery. The patient had a background of hepatitis B cirrhosis, which is the most phenomenon in China. Surgeons usually unable to distinguish sclerotic nodules from small tumor tissue with the naked eyes. Case Description: A 55-year-old man with chronic hepatitis B infection was preoperatively diagnosed with a space-occupying liver lesion. A fluorescence signal was detected on the surface of the liver through the NIRF imaging system which had not been found by preoperative computed tomography (CT) and ultrasound examination. We subsequently tested the residual liver surface and observed a high signal point, less than 1 mm in the right anterior lobe of the liver. Histopathological examination revealed that the tiny fluorescent spot belong to an early HCC focus. Conclusions: Based on these results, we think indocyanine green (ICG)-NIRF imaging may be used as a routine intraoperative detection method for liver cancer surgery in order to remove any residual tumor cells and tissue, hence minimizing further risk of remnant tumor regrowth.