An 85-year-old woman who had no history of chronic liver disease (viral infection and cirrhosis) was being followed-up for gallbladder polyps and was found to have a tumor in the liver. The patient was referred to our hospital because the tumor size was increasing. She had no subjective symptoms, abdominal pain, or fever. Her medical history showed hypertension, aneurysm clipping for cerebral hemorrhage, and gallstones. She had no history of smoking or drinking habit. There was no noteworthy family history. A detailed physical examination did not demonstrate any cardiovascular or pulmonary abnormalities. Laboratory data for all parameters, including tumor markers, were normal. Computed tomography (CT) scan showed that the tumor protruded outside the liver and appeared to contain two distinct components. The tumor component in segment IV in the liver was strongly enhanced, especially in the peripheral rim in the early and delayed arterial phase, followed by progressive hyperattenuation during the late phase. However, the extrahepatic protruding area was enhanced only in the surrounding area; no enhancement was observed inside, suggesting an abscess-like cystic structure. Ultrasound (US) also indicated that there were two components in one continuous tumor. US revealed that there was a hyperechoic component in the liver and that the protrusion area showed hypoechoicity. In contrast-enhanced US, the intrahepatic tumor showed vascularity in the early phase and showed a defect in the Kupffer phase. In the extrahepatic protrusion, the surrounding area was strongly enhanced in a capsule shape with a spot-like inflow of contrast medium observed inside. Therefore, the extrahepatic region was considered to be a tumor component rather than a cystic structure such as an abscess or hematoma. Magnetic resonance imaging (MRI) with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) revealed that the tumor was seen 4 cm in a diameter, had a clear margin, and contained two components. The tumor showed low signal intensity on T1-weighted images and a slightly high signal intensity on T2-weighted images. T1-weighted dynamic contrast-enhanced MRI showed strong enhancement in the intrahepatic tumor and slight enhancement in the capsule-like outside of the extrahepatic tumor in the early phase. In the late phase, the intrahepatic tumor showed high-intensity at the peripheral rim and gradually showed low-intensity in other parts. Finally, each area clearly showed a defect in the hepatobiliary phase. In diffusion-weighted images, a slightly hyperintense signal in all areas of the tumor was observed. In this case, the patient had no background history of hepatitis, obesity, alcohol, and diabetes. Additionally, there was no increase in the expression of tumor markers or inflammatory response, and the images were nonspecific, all of which made the diagnosis difficult. We initially suspected ICC in the liver tumor, but we could not explain the protrusion outside the liver. We realized that if the extrahepatic component was an abscess or hematoma, the blood flow inside the nodule was inconsistent. Furthermore, if the intrahepatic tumor was ICC, it was unlikely that it would rupture and form a hematoma outside the liver. We confirmed that there was no cholecystitis, and that the intestinal tract was not adhered, but we did not consider the mesenchymal lesions. Since imaging diagnosis did not lead to a definitive diagnosis of the tumor, we initially planned for diagnostic laparoscopic surgery. After laparoscopic observation, if an abscess was suspected, a partial excision was to be performed; if cancer was diagnosed after the excision, additional excision was to be performed in two stages if necessary. However, left hepatectomy was planned if ICC was suspected laparoscopically. After informing the patient of the likelihood of tumor growth and diagnostic purpose of the procedure, we obtained informed consent from the patient. When observing the lesion laparoscopically, a white nodule was visible on the surface of the falciform ligament, suggesting carcinoma. The mesentery was swollen and felt as if it contained a hard mass. Intraoperative US observation also confirmed the presence of a mass in the falciform ligament. By direct laparoscopic observation, we determined that the lesions identified as extrahepatic lesions by preoperative imaging were malignant tumors. ICC originates from the endothelial cells of the segmental or proximal branches of the bile duct. Unfortunately, ICC has a high incidence of locoregional recurrence even after surgery. Couinaud’s segments, sectors and hemilivers resection are recommended to carried out if the degree of liver fibrosis and future liver remnant volume are acceptable. In our patient, the total liver volume was estimated to be 830 mL, and the excision volume was estimated to be 31%. Since the residual liver volume was 570 mL (69%), it was judged that left hepatectomy was possible. Left hepatectomy and cholecystectomy were performed laparoscopically. The patient experienced no postoperative complications and was discharged home 10 days after the operation. Macroscopically, there was a 15-mm white nodule in the liver and a 29-mm white nodule in the mesentery. There was no continuity between the two nodules. Tumors in the liver were fibrous, hard, and non-capsular, whereas those in the mesentery were capsular and soft, with internal hemorrhage accompanying the capsule. Microscopically, the tumor showed glandular and papillary growth patterns with small amount of fibrosis and infiltration of the inflammatory cells. The neoplastic cells were columnar and cuboidal and showed high nucleo-cytoplasmic ratio. The tumor was diagnosed as an ICC. Multiple vascular invasions were observed around the tumor and neural invasion was also observed. The Ki-67 score was high, at 57 %. The structures of the extrahepatic tumor were histologically similar to that of the intrahepatic main tumor. The extrahepatic tumor had extensive necrosis in the center and viable cells remained only in the peripheral area. There were no infiltrates in the round ligament of the liver, and several tumor thrombi were found in the small veins of the falciform ligament. Overall, the extrahepatic tumor was diagnosed as hematogenous metastasis of ICC. The preoperative CT scan was unclear because no angiography was performed; however, falciform ligament artery (FLA) seems to be branched from A4 on arterial phase of contrast-enhanced CT.