Case report of ectopic hepatic tissue, a rare finding during a laparoscopic cholecystectomy

A case of hepatocellular carcinoma arising from the intraductal hepatic bile duct without parenchymal lesion

Hepatocellular carcinoma (HCC) rarely presents as an intraductal tumor with no parenchymal lesions. Here, we present a case of HCC arising from an intrahepatic bile duct. A 74-year-old man who had been treated with direct-acting antiviral therapy for hepatitis C virus infection was referred to our hospital because of elevated serum prothrombin levels induced by vitamin K absence II (PIVKA-II). Initial imaging revealed no findings suspicious of HCC; however, repeat CT six months later revealed dilation of the intrahepatic bile ducts in the lateral segment of the liver. Cholangiography revealed a significant stricture of B3, and biopsy suggested adenocarcinoma. A left hepatectomy was performed with a preoperative diagnosis of intrahepatic cholangiocarcinoma. Although a surface nodule on the lateral segment of the liver, suspicious for intrahepatic metastasis, was found intraoperatively, radical resection was performed. Histopathological examination revealed a tumor filling the intrahepatic bile duct from the stump to the peripheral bile duct, with no infiltration into the liver parenchyma. The surface nodule is a dilated peripheral bile duct filled with a tumor with no extrabiliary invasion. Immunohistochemistry suggested HCC. No tumor lesions were observed in the hepatic parenchyma, and the tumor was finally diagnosed as HCC stemming from the biliary epithelium.

Ectopic Liver Tissue Associated With the Gallbladder: Two Unique Patients and a Literature Review

Ectopic/accessory liver tissue is a rare developmental anomaly thought to be due to abnormal development of the liver during embryogenesis. Most patients with ectopic liver tissue are asymptomatic, and the condition is usually discovered incidentally during intraabdominal surgery or autopsy. In rare symptomatic cases, patients' presentations can range from mild liver function test abnormalities to severe abdominal pain or discomfort secondary to torsion and ischemia. Here, we report 2 patients with ectopic liver tissue identified incidentally during cholecystectomy: one with histologic manifestations of sickle cell congestion and the other with steatohepatitis. A possible relationship between ectopic liver tissue and gallbladder and biliary diseases, such as cholecystitis, has been proposed. To the best of our knowledge, ectopic liver tissue with sickle cell congestion has not been reported previously.

Ectopic Hepatocellular Carcinoma in the Gallbladder Wall With Choledocholithiasis: A Case Report

An ectopic hepatocellular carcinoma (HCC) that originates from the ectopic liver is defined as a hepatic organ or tissue not conventionally linked to surrounding tissues. Ectopic HCC has a rare clinical incidence, and diagnosing it before surgery is challenging. Its characteristics and biological behavior have not been fully elucidated. This report presents a unique case of ectopic HCC in the gallbladder, discontinuous with the liver. A 74-year-old man was referred to our hospital after primarily complaining of fever and right hypochondrium pain. Plain computed tomography revealed a significantly thickened gallbladder wall containing fluid collection and incarceration of gallstone in the common bile duct. He was diagnosed with acute cholecystitis and obstructive cholangitis due to choledocholithiasis. After percutaneous transhepatic gallbladder drainage and endoscopic lithotomy for choledocholithiasis, a cholecystectomy was performed. Macroscopically, the resected gallbladder had a yellowish tumor (1 cm) within the significantly thickened gallbladder wall. Histopathological examination identified moderately differentiated HCC on the ectopic liver, discontinuous with the liver. Immunohistologically, the tumor was finally diagnosed as ectopic HCC with alpha-fetoprotein positive expression.

The First Case Report of Ectopic Hepatic Tissue in a Guinea Pig

Ectopic hepatic tissue is an extremely rare developmental abnormality in human beings. Although this lesion is likewise rare in veterinary medicine and there were sparse reports in several species such as dogs, cats, cows, and calves, we incidentally encountered ectopic hepatic tissue in a guinea pig. In the case of guinea pigs, we report for the first time the occurrence of ectopic hepatic tissue implanted in the gallbladder. The healthy guinea pig remained asymptomatic, and its macroscopic findings also showed no abnormalities. Hematological examinations exhibited moderate decreases in white cell counts, hemoglobin concentrations, and packed cell volume ratio. Serum biochemical examinations showed decreases in total protein and albumin and increases in glucose levels, alkaline phosphatase, lactate dehydrogenase, creatine kinase, and γ-glutamyl transpeptidase. There were slight changes in electrolytes (Cl, Ca, and Mg) and inorganic phosphorus, indicating minor deviations from physiologic ranges. An increase in TBIL concentrations was not found in this examination. Histopathological examination revealed the presence of normal hepatic structures (hepatocytes and hepatic cords) within the wall of the normal gallbladder. The vascular and bile duct structures and portal triads were not observed in the ectopic hepatic tissue. In conclusion, this microectopic hepatic tissue in a guinea pig was characterized by the embedded structures of hepatic tissues, without foreign body reaction.

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.