Accessory liver lobe attached to the wall of the gallbladder: a cadaveric case report

Ectopic liver tissue (choristoma) on the gallbladder: A comprehensive literature review

BACKGROUND

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.

AIM

To identify studies in the literature on ectopic liver tissue located on the gallbladder surface or mesentery.

METHODS

We present two patients and review published articles on ectopic liver tissue located on the gallbladder surface accessed via PubMed, MEDLINE, Google Scholar, and Google databases. Keywords used included 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. Letters to the editor, case reports, review articles, original articles, and meeting presentations were included in the search. Articles or abstracts containing adequate information on age, sex, history of liver disease, preliminary diagnosis, radiologic tools, lesion size, surgical indication, surgical procedure, and histopathological features of ectopic liver tissue were included in the study.

RESULTS

A total of 72 articles involving 91 cases of ectopic liver tissue located on the gallbladder surface or mesentery were analyzed. Of these 91 patients, 62 were female and 25 were male (no gender available for 4 patients), and the age range was 5 d to 91 years. Forty-nine patients underwent surgery for chronic cholecystitis or cholelithiasis, and 14 patients underwent surgery for acute cholecystitis. The remaining 28 patients underwent laparotomy for other reasons. Cholecystectomy was laparoscopic in 69 patients and open in 11 patients. The remaining 19 patients underwent various other surgical procedures such as autopsy, liver transplantation, living donor hepatectomy, Whipple procedure, and liver segment V resection. Histopathologically, hepatocellular carcinoma was detected in the ectopic liver tissue of one patient.

CONCLUSION

Ectopic liver tissue is a rare developmental anomaly which is usually detected incidentally. Although most studies suggest that ectopic liver located outside the gallbladder has a high risk of hepatocellular carcinoma, this is not reflected in statistical analysis.

Accessory liver lobe of the gallbladder in adults

The accessory liver lobe (ALL) of the gallbladder wall is rare, mentioned by Meckel since 1822. We present two cases of ALL occurring in two adult women. The ALLs were diagnosed at microscopic examination of cholecystectomy specimens for lithiasic cholecystitis and were located at the gallbladder body level. They measured 0.5 and 1.1 cm and were pediculated from the gallbladder serosa. Luschka duct complexes were seen in the adjacent subserosa in one of the cases. The main clinical relevance of ALL of the gallbladder resides in the differential diagnosis with a lymph node and in the risk of peroperative hemorragia or bile leakage by sectioning of the connecting blood vessels and/or bile duct. Intraparietal ALL may interfere with dysmotility, possibly resulting in bile stagnation and stone formation.