A 74-year-old woman was found to have a hepatic mass based on CT findings. She was diagnosed as having cecum cancer, and it was difficult to distinguish whether the hepatic mass was liver metastasis or biliary cystadenocarcinoma. We proceeded with the surgery for cecum cancer, and laparoscopic ileocecal resection with D3 lymph node dissection was performed. The histopathological diagnosis was mucinous adenocarcinoma, and the pathological stage was T3N2H1P0M1a, Stage IV. After the surgery, her CEA level was elevated, and we diagnosed the hepatic mass as a liver metastasis. A CapeOX plus bevacizumab regimen was administered but was discontinued for 2 courses due to the development of adverse effects and her decision. Gd-EOB-DTPA-enhanced MRI revealed a multilocular and lobulated mass, which was a low-intensity area in T1WI and high-intensity area in T2WI, and the mass had no significant contrast effects. These images were unspecific for liver metastasis of colorectal cancer, and we performed segmental 6 hepatectomy for diagnosis and curative surgery. A histopathological diagnosis of liver metastasis of cecum cancer was made. Here, we report a case of liver metastasis of colorectal cancer that was undifferentiated from biliary cystadenocarcinoma.