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World J Gastrointest Surg. Jun 27, 2026; 18(6): 118136
Published online Jun 27, 2026. doi: 10.4240/wjgs.118136
Ectopic liver tissue on the gallbladder: A Preferred Reporting Items for Systematic Reviews and Meta-analyses guided systematic review
Sami Akbulut, Adem Tuncer
Sami Akbulut, Surgery and Liver Transplantation, Inonu University Faculty of Medicine, Malatya 44280, Türkiye
Sami Akbulut, Biostatistics and Medical Informatics, Inonu University Faculty of Medicine, Malatya 44280, Türkiye
Adem Tuncer, Surgery, Istanbul Aydın University Faculty of Medicine, Istanbul 34280, Türkiye
Author contributions: Akbulut S conducted a statistical analysis; Akbulut S and Tuncer A collected data, wrote manuscript projected development and reviewed final version.
AI contribution statement: The authors used an AI-assisted language tool only for language polishing, grammar correction, and improving the clarity and readability of the manuscript. No AI tool was used to generate the scientific content, design the study, collect or analyze data, interpret the results, or draw conclusions. All intellectual content, scientific interpretation, critical revisions, and final approval of the manuscript were performed solely by the authors. The authors take full responsibility for the accuracy, integrity, and originality of the submitted work.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Corresponding author: Sami Akbulut, MD, PhD, FACS, Professor, Surgery and Liver Transplantation, Inonu University Faculty of Medicine, Elazig Yolu 10 Kilometers, Malatya 44280, Türkiye. akbulutsami@gmail.com
Received: December 25, 2025
Revised: February 17, 2026
Accepted: April 1, 2026
Published online: June 27, 2026
Processing time: 173 Days and 5.4 Hours
Abstract
BACKGROUND

Ectopic liver tissue (ELT) is a rare congenital anomaly characterized by hepatic parenchyma located outside the native liver without anatomical continuity. The gallbladder surface or its mesentery represents the most frequent intra-abdominal location, where ELT is typically discovered incidentally during cholecystectomy or other abdominal procedures. Although most lesions are clinically silent and histologically benign, ELT may exhibit structural and metabolic vulnerabilities related to aberrant vascular and biliary drainage, predisposing it to complications such as torsion, ischemia, and, rarely, malignant transformation. Owing to its rarity, available evidence is largely limited to case reports and small series, resulting in heterogeneous terminology, inconsistent reporting, and uncertainty regarding true incidence, clinicopathological features, and optimal surgical management.

AIM

To systematically synthesize the available literature on ELT associated with the gallbladder, with particular emphasis on demographic characteristics, anatomical features, clinical presentation, diagnostic modalities, surgical management, histopathological findings, and the potential risk of malignant transformation.

METHODS

This systematic review adhered to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and was registered in International Prospective Register of Systematic Reviews (No. CRD420251114781). A literature search was conducted in PubMed, MEDLINE, Scopus, Web of Science, and Google Scholar for studies published up to August 1, 2025, without language restrictions. Search terms combined free-text and Medical Subject Headings terms such as “accessory liver lobe”, “ectopic liver tissue”, “hepatic choristoma”, and related phrases specific to the gallbladder. Studies reporting ELT located on the gallbladder were included. Data extraction covered demographics, anatomical site, clinical features, diagnostics, surgical approach, histopathology, and malignancy potential. Two reviewers independently extracted data and assessed study quality, resolving discrepancies by consensus.

RESULTS

A total of 97 articles containing 121 cases of ELT located on the gallbladder surface or its mesentery meeting the aforementioned criteria were analyzed. Additionally, three new cases from our study bring the total to 124 patients. Among them, 82 were female, 38 were male, and 4 had no available sex data. Their ages ranged from 5 days to 91 years among 119 patients; this information was unavailable for the remaining 5 patients. Surgical indications varied, with 52 patients undergoing surgery for cholelithiasis and associated conditions, 23 for acute cholecystitis and related diseases, 10 for presumed chronic cholecystitis, and the remaining patients for various other indications. Laparoscopic cholecystectomy was performed in 85 patients, open cholecystectomy in 18, and various other surgical or diagnostic procedures in 21 patients, histopathological evaluation revealed that ELT exhibited normal hepatic architecture in most cases (n = 106), while 10 patients presented with histopathological abnormalities such as steatohepatitis, cirrhosis, and hepatocellular carcinoma (n = 3). Histopathological details of the ELT tissue could not be obtained for the remaining 8 patients.

CONCLUSION

ELT is a rare congenital anomaly often detected incidentally during surgery. This review represents the first comprehensive and detailed systematic analysis in the literature focusing on gallbladder-associated ELT. Although the risk of malignant transformation remains uncertain, reported histopathological abnormalities including hepatocellular carcinoma highlight the need for careful evaluation.

Keywords: Liver; Gallbladder; Ectopic liver tissue; Hepatic choristoma; histopathological features; Hepatocellular carcinoma

Core Tip: Ectopic liver tissue (ELT) associated with the gallbladder is an uncommon congenital anomaly, most often detected incidentally during cholecystectomy. Evidence regarding its clinical relevance, optimal management, and malignant potential remains fragmented due to reliance on isolated case reports. This Preferred Reporting Items for Systematic Reviews and Meta-analyses-guided systematic review synthesizes data from 97 published articles and additional cases to clarify demographic features, anatomical characteristics, surgical approaches, and histopathological outcomes of gallbladder-associated ELT. Although most lesions exhibit normal hepatic architecture, reported cases of hepatocellular carcinoma underscore the importance of recognition and complete excision with histopathological evaluation when ELT is encountered intraoperatively.

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