Liver Agenesis Research Articles

Agenesis of Left Hepatic Lobe: A Rare Congenital Anomaly. Case Report

Morphologic anomalies of the liver, as opposed to many other visceral organs, are very rare. Left lobe liver agenesis is defined as the absence of liver tissue on the left side of the liver in the absence of previous disease or surgery. It is commonly an accidental finding on imaging investigations or at the time of abdominal surgery. We report the case of left liver lobe agenesis diagnosed in a 68-year-old man with a history of urothelial carcinoma of the bladder, and the diagnosis of his liver congenital abnormality was made accidentally on a CT of chest-abdomen-pelvis (initially done to look for secondary localisations of his urothelial carcinoma). The main imaging findings of this condition are reviewed briefly, with associations and the most common differential diagnoses.

Agenesis of Left Hepatic Lobe: A Rare Congenital Anomaly

Morphologic anomalies of the liver, as opposed to many other visceral organs, are very rare. Left lobe liver agenesis is defined as the absence of liver tissue on the left side of the liver in the absence of previous disease or surgery. It is commonly an accidental finding on imaging investigations or at the time of abdominal surgery. We herein report the case of left liver lobe agenesis diagnosed in a 70-year-old woman with a history of chronic abdominal pain. The diagnosis was confirmed by ultrasonography (US) and enhanced computed tomography (CT) investigations. The main imaging findings of this condition are reviewed briefly, with associations and the most common differential diagnoses.

Left Liver Agenesis in a Patient Undergoing Laparoscopic Surgery for Gastric Adenocarcinoma: a Case Report

Liver agenesis is a rare anomaly that courses with total absence of a hepatic lobe. There are few cases reported in the literature. We present a case of a patient with left liver agenesis, who underwent surgery for gastric adenocarcinoma. A 68-year-old male patient with no relevant medical history had recently been diagnosed with gastric cancer. On the pre-operative computer tomography (CT) scan and during surgery, an absence of the left liver was found. Liver agenesis is a rare medical condition and it is usually asymptomatic. In patients undergoing surgery, a clear diagnosis, preferentially in the pre-operative setting, is recommended to avoid misinterpretations and complications during surgery.

Unique functions of Gata4 in mouse liver induction and heart development

Gata4 and Gata6 are closely related transcription factors that are essential for the development of a number of embryonic tissues. While they have nearly identical DNA-binding domains and similar patterns of expression, Gata4 and Gata6 null embryos have strikingly different embryonic lethal phenotypes. To determine whether the lack of redundancy is due to differences in protein function or Gata4 and Gata6 expression domains, we generated mice that contained the Gata6 cDNA in place of the Gata4 genomic locus. Gata4Gata6/Gata6 embryos survived through embryonic day (E)12.5 and successfully underwent ventral folding morphogenesis, demonstrating that Gata6 is able to replace Gata4 function in extraembryonic tissues. Surprisingly, Gata6 is unable to replace Gata4 function in the septum transversum mesenchyme or the epicardium, leading to liver agenesis and lethal heart defects in Gata4Gata6/Gata6 embryos. These studies suggest that Gata4 has evolved distinct functions in the development of these tissues that cannot be performed by Gata6, even when it is provided in the identical expression domain. Our work has important implications for the respective mechanisms of Gata function during development, as well as the functional evolution of these essential transcription factors.

Liver agenesis with omphalocele: a report of two human embryos using serial histological sections.

We identified 2 human embryos, with crown-rump lengths (CRLs) of 22 mm and 23 mm and a gestational age of approximately 7 weeks (O'Rahilly's stage 21-22), with liver agenesis and omphalocele. Serial histological sections were prepared of the entire body of one specimen, whereas sections of the neck, including the upper part of the heart, were missed for the other specimen as a result of tissue damage during the abortion. In addition, isolated omphalocele was assessed in another embryo (CRL = 25 mm) for comparison with atypical omphalocele in the embryos with liver agenesis. The 2 embryos with liver agenesis were characterized by (1) the absence of the anterior part of the diaphragm; (2) abnormality in the venous pole of the heart; (3) a normal stomach in the left upper abdominal cavity; and (4) normal pancreas development with normal midgut rotation. The most likely cause of liver agenesis, when combined with isolated omphalocele, was a defect in the anterior extension or migration of the septum transversum rather than a mechanical separation of the hepatic diverticulum from the septum transversum.

Biliary injury after cholecystectomy in a patient with severe right liver atrophy

We report a case of bile fistula after cholecystectomy in a patient with severe right liver atrophy, which was managed by endoscopic nasobiliary drainage and conservative treatment. The patient was a 76-year-old man with a sudden onset in the right flank and abdominal pain. Computed tomography revealed calculous cholecystitis and severely atrophied right lobe of the liver. Gallbladder was located in the superior-posterior portion of the liver as opposed to the normal position. The patient underwent cholecystectomy and showed massive bleeding and bile leakage at the gallbladder bed during operation. A bile fistula was detected three days after surgery, which was managed by interventional bile drainage. Right liver agenesis or severe atrophy is rare. Additionally, the report of combined bile duct injury after cholecystectomy in these settings is extremely rare.

Interplay between Wnt2 and Wnt2bb controls multiple steps of early foregut-derived organ development

The vertebrate liver, pancreas and lung arise in close proximity from the multipotent foregut endoderm. Tissue-explant experiments uncovered instructive signals emanating from the neighbouring lateral plate mesoderm, directing the endoderm towards specific organ fates. This suggested that an intricate network of signals is required to control the specification and differentiation of each organ. Here, we show that sequential functions of Wnt2bb and Wnt2 control liver specification and proliferation in zebrafish. Their combined specific activities are essential for liver specification, as their loss of function causes liver agenesis. Conversely, excess wnt2bb or wnt2 induces ectopic liver tissue at the expense of pancreatic and anterior intestinal tissues, revealing the competence of intestinal endoderm to respond to hepatogenic signals. Epistasis experiments revealed that the receptor frizzled homolog 5 (fzd5) mediates part of the broader hepatic competence of the alimentary canal. fzd5 is required for early liver formation and interacts genetically with wnt2 as well as wnt2bb. In addition, lack of both ligands causes agenesis of the swim bladder, the structural homolog of the mammalian lung. Thus, tightly regulated spatiotemporal expression of wnt2bb, wnt2 and fzd5 is central to coordinating early liver, pancreas and swim bladder development from a multipotent foregut endoderm.

Agenesis of the Right Liver: A Difficult Laparoscopic Cholecystectomy

Congenital agenesis of the right liver (ARL) is a rare condition that is generally asymptomatic. Congenital anomalies of the liver are generally diagnosed with current cross-sectional imaging modalities such as ultrasound, computed tomography, and magnetic resonance imaging (MRI) before surgery. However, discovery of a congenital anomaly of the liver only at time of surgery remains a possibility. Herein reported is the case of a 68-year-old woman undergoing laparoscopic cholecystectomy for symptomatic gallbladder stones as diagnosed on preoperative ultrasounds. Upon laparoscopic exploration of the upper abdomen, the right liver was not found; the gallbladder was located in the right subdiaphragmatic region posterior to the medial segment of the liver. A posterolateral interposition of the hepatic flexure of the colon was also found. Cholecystectomy was completed under laparoscopy. A postoperative MRI confirmed right liver agenesis. We discuss the technical difficulties of performing a laparoscopic cholecystectomy in the case of ARL and the advantages of a laparoscopic approach.

Prenylcysteine carboxylmethyltransferase is essential for the earliest stages of liver development in mice

Background & Aims: Liver development, regeneration, and oncogenesis involve signaling events mediated by a number of proteins, such as ras and the related small guanosine triphosphatases. Many of these signaling proteins carry unique CAAX motifs, which are processed by prenylcysteine carboxylmethyltransferase (PCCMT), among several other enzymes. We investigated the function of Pccmt during mouse liver development to better understand the embryonic lethality of the null mutation. Methods: Generation of Pccmt-null mice by embryonic stem cell technology, molecular and histologic analysis of Pccmt-null embryos, and foregut endoderm cultures. Results:Pccmt-null embryos die in utero with severe anemia and extensive apoptosis at embryonic day 10.5. We show that deletion of Pccmt leads to a dramatic delay in albumin induction, an early and definitive marker for hepatocyte development. In tissue explant cultures supplemented with fibroblast growth factor (FGF), albumin induction remained impaired. We found that hepatocyte precursors in Pccmt-null embryos failed to invade the septum transversum, resulting in liver agenesis. Conclusions: PCCMT is essential for several stages of hepatic induction, consistent with its role in modifying proteins required to transduce signals, such as FGF, that have been shown to promote liver specification and early growth.GASTROENTEROLOGY 2002;123:345-351