A Case Report on Intrahepatic Cholangiocarcinoma with Suspected Indocyanine Green Excretory Defects: Clinical Decision Making for Hepatic Reserve Function Assessment?

Background: Indocyanine green (ICG), an organic dye with good fluorescence properties, is mainly excreted through the liver. The ICG test is widely used for the preoperative assessment of liver reserve function in partial hepatectomy or for marking the resection range of the lesion during the operation. Defects in the ICG excretory areextremely rare. When combined with liver tumors, these methodsoften causegreat confusion in clinical decision-making for such patients. Case presentation: In this study, we reported a case of intrahepatic cholangiocarcinoma complicated by suspected dysfunction in indocyanine green excretory defect. The patient underwent a subsequent successful surgical intervention; however, disease recurrence and metastasis were observed during follow-up. We conducted a comprehensive review of the existing literature on similar cases and summarized current methods for assessing liver function. Based on an analysis of the strengths and limitations of these methods, we proposed several recommendations for clinical practice. Conclusions: When the ICG clearance test reveals an isolated abnormality while other diagnostic evaluations remain normal, we suggest further assessment via the ALICE grading system. If the ALICE grade is 1, surgical resection may proceed directly. However, if the ALICE grade is 2 or 3, additional diagnostic tools—such as three-dimensional liver imaging, liver elastography, and the liver maximum capacity (LiMAx) test—should be employed to more accurately evaluate functional liver reserve (FLR). For patients diagnosed with ICG excretory defects, gadoxetic acid disodium (Gd-EOB)-enhanced magnetic resonance imaging (MRI) or scintigraphy should be avoided whenever possible, as these modalities rely on the function of organic anion transporting polypeptides (OATP1B1 and OATP1B3), which may also be impaired.