Isolated liver metastasis detected 11 years after the curative resection of rectal cancer: A case report

BACKGROUNDThe duration of surveillance after curative resection of colorectal cancer (CRC) is generally 5 years. The overall incidence of recurrence more than 5 years after surgery for CRC in Japan has been reported to be 0.6%. Moreover, it is rare for CRC to have metachronous liver metastasis more than 10 years after surgery. Here, we present a case of liver metastasis detected 11 years after the curative resection of rectal cancer.CASE SUMMARYA 72-year-old man was referred to our hospital after a liver tumor was detected by abdominal ultrasonography at another hospital. He had undergone surgery for rectal cancer 11 years previously. Contrast-enhanced computed tomography (CT) showed a tumor with a diameter of approximately 8 cm in the posterior segment, which was weakly and gradually enhanced. ¹⁸F-fluorodeoxyglucose-positron emission tomography/CT showed an abnormally high uptake on the tumorous lesion, which showed that the tumor appeared to spread convexly along the intrahepatic bile ducts. Intrahepatic cholangiocarcinoma was therefore diagnosed, and he had an extended right posterior sectionectomy and regional lymph node dissection. Histopathological examination showed that the tumor was a moderately differentiated adenocarcinoma and showed the same pathological characteristics as the rectal cancer. Immunohistological examination showed that the cancer cells of both the liver tumor and rectal cancer were positive for cytokeratin (CK) 20 and weakly positive for CK 7. These findings were consistent with the liver metastasis from the rectal cancer.CONCLUSIONIt is possible that a liver tumor is metastatic in a patient with a previous history of CRC, even if it was more than 10 years earlier.