A Case of Accessory Liver Discovered as a Nodule on the Gallbladder Wall during Ascending Colon Cancer Surgery

Abstract

A patient with accessory liver discovered during preoperative investigations for ascending colon cancer that was difficult to distinguish from a hepatic portal lymph node is presented. A 73-year-old woman was scheduled to undergo surgery for ascending colon cancer (T1bN0). A 9-mm, contrast-enhanced, nodular shadow in the hepatic portal region was observed on preoperative abdominal contrast-enhanced computed tomography (CT), and hepatic portal lymph node metastasis could not be excluded. Laparoscopic-assisted right hemicolectomy for the ascending colon cancer was scheduled, and it was decided that, if hepatic portal lymph node metastasis was suspected from intraoperative findings, then the lymph node would be submitted for rapid intraoperative pathological diagnosis. Intraoperatively, a brown nodule, 10 mm in size, was observed to be attached to the serosal surface of the body of the gallbladder. There was no continuity with the liver parenchyma, but since it was in communication with the medial segment of the liver and the gall bladder via vascular channels, it was diagnosed as an accessory liver and excised. The histopathological findings were not inconsistent with liver parenchyma, and there were no signs of malignancy or other atypical findings. An accessory liver is a rare condition, with only around 100 reported cases in Japan. This case is reported and compared with the other Japanese reported cases, with a short discussion of the literature.