Published online Dec 27, 2020. doi: 10.4240/wjgs.v12.i12.534
Peer-review started: September 26, 2020
First decision: October 21, 2020
Revised: November 12, 2020
Accepted: December 2, 2020
Article in press: December 2, 2020
Published online: December 27, 2020
Liver tissue situated outside the liver with a hepatic connection is usually called an accessory liver, and that without a connection to the mother liver, is called ectopic liver tissue. Ectopic liver tissue is a rare developmental anomaly usually detected incidentally.
Although a limited number of case reports on ectopic liver tissue on the gallbladder surface or gallbladder mesentery have been published to date, no systematic literature research has been conducted.
While the main objective of this study was to review the articles published in the medical literature on ectopic liver tissue on the gallbladder surface or gallbladder mesentery, the secondary objective of this study was to present the medical history of two patients diagnosed with ectopic liver tissue.
A systematic literature search was conducted on PubMed, Medline, Google Scholar, and Google databases using the following keywords: Accessory liver lobe, aberrant liver tissue, ectopic liver tissue, ectopic liver nodule, heterotopic liver tissue, hepatic choristoma, heterotopic liver tissue on the gallbladder, and ectopic liver tissue on the gallbladder. The search included articles published before June 2020 with no language restriction.
A total of 72 articles were identified involving 91 patients, 62 females and 25 males; no gender data were available for the remaining four patients. The age of these 87 patients ranged from five days to 91 years; this information was unavailable for the remaining four patients. Eleven patients had a history of various liver diseases, while 12 patients had no liver disease. Forty-nine patients had surgery for chronic cholecystitis and/or cholelithiasis, while 14 patients had surgery for a presumed diagnosis of acute cholecystitis. The remaining 28 patients underwent laparotomy for unrelated reasons. Sixty-one patients underwent laparoscopic cholecystectomy and 11 underwent open cholecystectomy. The remaining 19 patients underwent cholecystectomy and various surgical procedures such as autopsy, liver transplantation, living donor hepatectomy, Whipple procedure, and liver segment V resection.
Ectopic liver tissue is a rare developmental anomaly usually detected incidentally during surgery or autopsy. While it is often asymptomatic, it has a risk of malignant transformation and carries the potential of other complications such as bleeding and torsion.
First, a review of the literature and our clinical experience suggest that ectopic liver tissue-like lesions around the liver should be considered in the differential diagnosis of ectopic hepatocellular carcinoma, especially in patients with chronic liver disease. Therefore, even when the macroscopic appearance is normal, all ectopic liver tissue specimens should be sent for routine histopathological examination. Second, although most studies have suggested that ectopic liver located outside the gallbladder has a higher risk of hepatocellular carcinoma, this is not reflected in the statistical analysis results.