Fibropolycystic liver disease in children

[A case of neonatal liver failure]

The patient was a male infant, born full-term, admitted to the hospital at 28 days of age due to jaundice for 20 days and abdominal distension for 15 days. The patient developed symptoms of jaundice, hepatosplenomegaly, massive ascites, and progressively worsening liver function leading to liver failure, severe coagulation disorders, and thrombocytopenia one week after birth. Various treatments were administered, including anti-infection therapy, fluid restriction, use of diuretics, use of hepatoprotective and choleretic agents, intermittent paracentesis, blood exchange, and intravenous immunoglobulin, albumin, and plasma transfusions. However, the patient's condition did not improve, and on the 24th day of hospitalization, the family decided to discontinue treatment and provide palliative care. Sequencing of the patient's liver tissue and parental blood samples using whole-exome sequencing did not identify any pathogenic variants that could explain the liver failure. However, postmortem liver tissue pathology suggested congenital hepatic fibrosis (CHF). Given the rarity of CHF causing neonatal liver failure, further studies on the prognosis and pathogenic genes of CHF cases are needed in the future. This article provides a comprehensive description of the differential diagnosis of neonatal liver failure and introduces a multidisciplinary diagnostic and therapeutic approach to neonatal liver failure.

An update on ductal plate malformations and fibropolycystic diseases of the liver

A variety of cystic and fibrocystic lesions can occur in the liver, which may be single or multiple and etiologically can be acquired or have genetic underpinnings. Although the morphology of ductal plate development and various associated malformations has been well described, the genetic etiologies of many of these disorders are still poorly understood. Multiple clinical phenotypes in the liver are proposed to originate from ductal plate malformations: congenital hepatic fibrosis, Caroli's disease, Von Meyenburg complex, and the liver cysts of autosomal dominant polycystic kidney and liver diseases. Although many of the patients with these disorders, particularly with isolated liver involvement remain asymptomatic, some develop portal hypertension or symptoms from cyst enlargement. Development of hepatocellular malignancy is a risk in a small subset. Recent advances have made it now possible for some of these phenotypes to be genetically defined, and intriguingly animal models of adult polycystic liver disease suggest that abnormal organ development is not required. This review describes the current understanding, genetic underpinning, and key clinicopathologic and imaging features of these fibropolycystic liver diseases.

Dysregulation of the Scribble/YAP/β-catenin axis sustains the fibroinflammatory response in a PKHD1-/- mouse model of congenital hepatic fibrosis

Congenital hepatic fibrosis (CHF), a genetic cholangiopathy characterized by fibropolycystic changes in the biliary tree, is caused by mutations in the PKHD1 gene, leading to defective fibrocystin (FPC), changes in planar cell polarity (PCP) and increased β-catenin-dependent chemokine secretion. In this study, we aimed at understanding the role of Scribble (a protein involved in PCP), Yes-associated protein (YAP), and β-catenin in the regulation of the fibroinflammatory phenotype of FPC-defective cholangiocytes. Immunohistochemistry showed that compared with wild type (WT) mice, in FPC-defective (Pkhd1^del4/del4 ) mice nuclear expression of YAP/TAZ in cystic cholangiocytes, significantly increased and correlated with connective tissue growth factor (CTGF) expression and pericystic fibrosis, while Scribble expression on biliary cyst cells was markedly decreased. Cholangiocytes isolated from WT mice showed intense Scribble immunoreactivity at the membrane, but minimal nuclear expression of YAP, which conversely increased, together with CTGF, after small interfering RNA (siRNA) silencing of Scribble. In FPC-defective cholangiocytes, inhibition of YAP nuclear import reduced β-catenin nuclear expression, and CTGF, integrin β6, CXCL1, and CXCL10 mRNA levels, whereas inhibition of β-catenin signaling did not affect nuclear translocation of YAP. Notably, siRNA silencing of Scribble and YAP in WT cholangiocytes mimics the fibroinflammatory changes of FPC-defective cholangiocytes. Conditional deletion of β-catenin in Pkhd1^del4/del4  mice reduced cyst growth, inflammation and fibrosis, without affecting YAP nuclear expression. In conclusion, the defective anchor of Scribble to the membrane facilitates the nuclear translocation of YAP and β-catenin with gain of a fibroinflammatory phenotype. The Scribble/YAP/β-catenin axis is a critical factor in the sequence of events linking the genetic defect to fibrocystic trait of cholangiocytes in CHF.

Hilar Fibropolycystic Liver Disease of Unknown Etiology: A Revelation from the Explant Liver

Fibropolycystic diseases of the liver comprise a spectrum of disorders affecting bile ducts of various sizes and arise due to an underlying ductal plate malformation (DPM). We encountered a previously unreported variant of DPM, the hilar fibropolycystic disease which we diagnosed in the explant liver. A 2-year-old boy was referred for liver transplantation with a diagnosis of biliary atresia (BA) and failed Kasai portoenterostomy (KPE). He had cirrhosis with portal hypertension along with synthetic failure indicated by coagulopathy and hypoalbuminemia. The child underwent liver transplant successfully. The explant liver had fibropolycystic disease confined to the perihilar liver and hilum. No pathogenic mutation was detected by whole exome sequencing. Fibropolycystic liver disease may represent a peculiar anatomical variant, which can be diagnosed by careful pathological examination of the explant liver. The neonatal presentation of hilar fibropolycystic liver disease can be misdiagnosed as BA.

Hepatic manifestations of systemic disease: an imaging-based review

The liver is responsible for many processes that maintain human metabolic homeostasis and can be affected by several pediatric systemic diseases. In this manuscript, we explore key pathological findings and imaging features across multiple modalities of a spectrum of congenital, metabolic and autoimmune disorders. Strengthening the radiologists' knowledge regarding potential hepatic manifestations of these systemic diseases will ultimately lead to improved care for pediatric patients.

Inflammatory pathways and cholangiocarcinoma risk mechanisms and prevention

Cholangiocarcinoma (CCA), a neoplasm burdened by a poor prognosis and currently lacking adequate therapeutic treatments, can originate at different levels of the biliary tree, in the intrahepatic, hilar, or extrahepatic area. The main risk factors for the development of CCA are the presence of chronic cholangiopathies of various etiology. To date, the most studied prodromal diseases of CCA are primary sclerosing cholangitis, Caroli's disease and fluke infestations, but other conditions, such as metabolic syndrome, nonalcoholic fatty liver disease and obesity, are emerging as associated with an increased risk of CCA development. In this review, we focused on the analysis of the pro-inflammatory mechanisms that induce the development of CCA and on the role of cells of the immune response in cholangiocarcinogenesis. In very recent times, these cellular mechanisms have been the subject of emerging studies aimed at verifying how the modulation of the inflammatory and immunological responses can have a therapeutic significance and how these can be used as therapeutic targets.

Diffuse Versus Localized Caroli Disease: A Comparative MRCP Study

OBJECTIVE. The purpose of this multicenter retrospective study was to assess the MRCP features of Caroli disease (CD). MATERIALS AND METHODS. Sixty-six patients were identified from 2000 to 2019. The inclusion criteria were diagnosis of diffuse or localized CD mentioned in an imaging report, presence of intrahepatic bile duct (IHBD) dilatation, and having undergone an MRCP examination. The exclusion criteria included presence of obstructive proximal biliary stricture and having undergone hepatobiliary surgery other than cholecystectomy. Histopathology records were available for 53 of the 66 (80%) patients. Diffuse and localized diseases were compared by chi-square and t tests and Kaplan-Meier model. RESULTS. Forty-five patients had diffuse bilobar CD ((five pediatric patients [three girls and two boys] with a mean [± SD] age of 8 ± 5 years [range, 1-15 years] and 40 adult patients [26 men and 14 women] with a mean age of 35 ± 11 years [range, 20-62 years]) and 21 patients had localized disease (12 men and 9 women; mean age, 54 ± 14 years). Congenital hepatic fibrosis was found only in patients with diffuse CD (35/45 [78%]), as was a "central dot" sign (15/35 [43%]). IHBD dilatation with both saccular and fusiform features was found in 43 (96%) and the peripheral "funnel-shaped" sign in 41 (91%) of the 45 patients with diffuse CD but in none of the patients with localized disease (p < .001). Intrahepatic biliary calculi were found in all patients with localized disease but in only 16 of the 45 (36%) patients with diffuse CD (p < .001). Left liver atrophy was found in 18 of the 21 (86%) patients with localized disease and in none of the patients with diffuse CD (p < .001). The overall survival rate among patients with diffuse CD was significantly lower than that among patients with localized disease (p = .03). CONCLUSION. Diffuse IHBD dilatation with both saccular and fusiform features associated with the peripheral funnel-shaped sign can be used for the diagnosis of CD on MRCP. Localized IHBD dilatation seems to be mainly related to primary intrahepatic lithiasis.

Caroli's Syndrome: An Early Presentation

Fibropolycystic liver disorders (FLD) arise from abnormal development of the ductal plate and are classified according to the size of the affected hepatobiliary duct. Congenital hepatic fibrosis (CHF) has small duct involvement characterized by a variable degree of periportal fibrosis and hyperplasia without affecting the liver’s architecture. Caroli’s disease (CD) is a rare autosomal recessive disorder with a prevalence of one case per 1,000,000 people and is characterized by cystic dilation of large intrahepatic ducts. When the disease presents with congenital hepatic fibrosis, it is referred to as Caroli’s syndrome (CS). Patients are usually diagnosed around the age of 20 with episodes of cholangitis, portal hypertension or hepatomegaly. We present the case of a two-year-old male with a previous history of autosomal recessive polycystic kidney disease (ARPKD) who presented to the emergency room with variceal bleeding secondary to portal hypertension. The physical examination showed an acutely ill-looking boy, with evident paleness and distended abdomen. Past medical history was negative for previous gastrointestinal bleeding or episodes of cholangitis. An upper gastrointestinal endoscopy was performed, showing esophageal varices secondary to portal hypertension. Imaging studies revealed hepatosplenomegaly, alterations in liver echogenicity, and dilated saccular bile ducts affecting both liver lobes without observing any apparent obstruction, highly suggestive of CD. A liver biopsy revealed nodular liver tissue with marked fibrosis between nodules, which confirmed the presence of CHF. Both kidneys were increased in size, hyperechoic and with loss of corticomedullary differentiation. FLD commonly present with coexisting hepatobiliary and renal alterations. Therefore, starting at the time of initial diagnosis, all patients with ARPKD should be evaluated to detect liver abnormalities due to the high association. Despite the rarity of CS, especially in early childhood, the association between ARPKD and FLD is well documented. So if this clinical presentation arises, CS should be suspected. 

Diagnosis of Congenital Hepatic Fibrosis in Adulthood

OBJECTIVES

We studied clinicopathologic features of congenital hepatic fibrosis (CHF) that could aid the diagnosis of this relatively rare condition during adulthood.

METHODS

Five consecutive adult CHF cases were identified in a single institution.

RESULTS

Clinical manifestations of CHF varied from asymptomatic to requiring liver transplantation. Three of five cases had other disease associations, including Joubert syndrome, Caroli disease, polycystic kidney disease, and congenital anomaly of hepatic vasculature. No unique common radiologic findings were found. Histologically, all cases showed characteristic abnormal interlobular bile ducts embedded in fibrotic portal stroma, with varying degrees of liver fibrosis.

CONCLUSIONS

While other disease associations and characteristic liver histomorphology are helpful clues to suspect the diagnosis of CHF in adult patients, other differential diagnoses should be excluded clinically and radiologically. This study highlights the importance of a multidisciplinary diagnostic approach by pathologists, radiologists, and hepatologists for the accurate diagnosis of CHF during adulthood.

Pathobiology of inherited biliary diseases: a roadmap to understand acquired liver diseases

Bile duct epithelial cells, also known as cholangiocytes, regulate the composition of bile and its flow. Acquired, congenital and genetic dysfunctions in these cells give rise to a set of diverse and complex diseases, often of unknown aetiology, called cholangiopathies. New knowledge has been steadily acquired about genetic and congenital cholangiopathies, and this has led to a better understanding of the mechanisms of acquired cholangiopathies. This Review focuses on findings from studies on Alagille syndrome, polycystic liver diseases, fibropolycystic liver diseases (Caroli disease and congenital hepatic fibrosis) and cystic fibrosis-related liver disease. In particular, knowledge on the role of Notch signalling in biliary repair and tubulogenesis has been advanced by work on Alagille syndrome, and investigations in polycystic liver diseases have highlighted the role of primary cilia in biliary pathophysiology and the concept of biliary angiogenic signalling and its role in cyst growth and biliary repair. In fibropolycystic liver disease, research has shown that loss of fibrocystin generates a signalling cascade that increases β-catenin signalling, activates the NOD-, LRR- and pyrin domain-containing 3 inflammasome, and promotes production of IL-1β and other chemokines that attract macrophages and orchestrate the process of pericystic and portal fibrosis, which are the main mechanisms of progression in cholangiopathies. In cystic fibrosis-related liver disease, lack of cystic fibrosis transmembrane conductance regulator increases the sensitivity of epithelial Toll-like receptor 4 that sustains the secretion of nuclear factor-κB-dependent cytokines and peribiliary inflammation in response to gut-derived products, providing a model for primary sclerosing cholangitis. These signalling mechanisms may be targeted therapeutically and they offer a possibility for the development of novel treatments for acquired cholangiopathies.

Magnetic resonance imaging of fibropolycystic liver disease: the spectrum of ductal plate malformations

Fibropolycystic liver diseases, also known as ductal plate malformations, are a group of associated congenital disorders resulting from abnormal development of the biliary ductal system. These disorders include congenital hepatic fibrosis, biliary hamartomas, polycystic liver disease, choledochal cysts and Caroli disease. Recently, it has been thought to include biliary atresia in this group of diseases, because ductal plate malformations could be implicated in the pathogenesis of this disease. Concomitant associated renal anomalies can also be present, such as autosomal recessive polycystic kidney disease (ARPKD), medullary sponge kidney and nephronophthisis. These disorders can be clinically silent or can cause abnormalities such as cholangitis, portal hypertension, gastrointestinal bleeding and infections. The different types of ductal plate malformations show typical findings at magnetic resonance (MR) imaging. A clear knowledge of the embryology and pathogenesis of the ductal plate plays a pivotal role to understand the characteristic imaging appearances of these complex diseases. Awareness of these MR imaging findings is central to the detecting and differentiating between various fibropolycystic liver diseases and is important to direct appropriate clinical management and prevent misdiagnosis.

Congenital Cystic Lesions of the Bile Ducts: Imaging-Based Diagnosis

Congenital cystic lesions of the bile ducts represent a spectrum of liver and biliary system lesions, resulting from abnormal embryologic development of the ductal plate. These disorders include Caroli disease, choledochal cysts, autosomal dominant polycystic liver disease, congenital hepatic fibrosis, and biliary hamartomas. Each disorder carries a peculiar clinical presentation, prognosis, and risk of complications. Knowledge of radiological findings of fibropolycystic liver diseases is crucial for their appropriate detection and for differential diagnosis with other similar hepatic cystic lesions, in order to avoid relevant misdiagnosis. The aim of this review is to provide an illustrative summary of the most relevant imaging findings of these conditions as encountered on ultrasound, computed tomography, and magnetic resonance imaging, and provide pearls for imaging-based differential diagnosis.

Malignant Transformation Arising Within Unusual and Rare Hepatic Lesions: Fibropolycystic Disease Form of Ductal Plate Malformation and Biliary Adenofibroma

Cholangiocarcinoma is the second most common hepatobiliary cancer following hepatocellular carcinoma, and 20% to 25% are intrahepatic. We describe 2 cases of intrahepatic cholangiocarcinoma arising within unusual and rare hepatic lesions, fibropolycystic liver disease form of ductal plate malformation and biliary adenofibroma, whose association with malignancy is rarely reported in the literature.

Abernethy malformation associated with Caroli's syndrome in a patient with a PKHD1 mutation: a case report

Background

Abernethy malformation is a rare congenital anomaly characterised by the partial or complete absence of the portal vein and the subsequent development of an extrahepatic portosystemic shunt. Caroli’s disease is a rare congenital condition characterised by non-obstructive saccular intrahepatic bile duct dilation. Caroli’s disease combined with congenital hepatic fibrosis and/or renal cystic disease is referred to - Caroli’s syndrome. The combination of Abernethy malformation and Caroli’s syndrome has not been reported previously.

Case presentation

We present the case of a 23-year-old female who was found to have both type II Abernethy malformation and Caroli’s syndrome. Radiological imaging was performed, including computed tomography with three-dimensional reconstruction and magnetic resonance imaging with (magnetic resonance cholangiopancreatography (MRCP), which revealed a side-to-side portocaval shunt, intrahepatic bile duct dilation, congenital hepatic fibrosis, and renal cysts. In addition, PKHD1 (polycystic kidney and hepatic disease 1) gene mutational analysis revealed a paternally inherited heterozygous missense mutation (c.1877A > G, p.Lys626Arg). A liver biopsy confirmed the pathological features of Caroli’s syndrome.

Conclusions

To our knowledge, this is the first reported case of a patient with both type II Abernethy malformation and Caroli’s syndrome diagnosed using a comprehensive approach that included imaging, mutational analysis, and liver biopsy. Additionally, this is the second reported case to date of an Asian patient presenting with liver and renal disorders with the same paternally inherited PKHD1 missense mutation.

Ultrasound of congenital and inherited disorders of the pediatric hepatobiliary system, pancreas and spleen

Ultrasound is often the initial imaging examination performed of the solid organs of the pediatric abdomen. The sonographic appearance of the hepatobiliary system, pancreas and spleen changes with growth and development. This article reviews the normal US appearance of these organs in children and illustrates, through case examples, congenital and inherited conditions that affect them.

Segmental cholangiectasia clinically worrisome for cholangiocarcinoma: comparison with recurrent pyogenic cholangitis

The aim of this study was to review the clinical, radiographic, and pathologic features of cases of benign segmental cholangiectasia in non-Asian US patients with clinical concern for cholangiocarcinoma and compare these features with cases of recurrent pyogenic cholangitis (RPC) in Asian patients. A total of 10 non-Asian US patients with benign segmental cholangiectasia were included in this study. Nine of them underwent partial hepatic resection due to cholangiographic findings of segmental cholangiectasia with mural thickening and/or proximal biliary stricture. One was found to have markedly dilated and thickened intrahepatic bile ducts at the time of autopsy. Clinical and radiographic findings were reviewed. Elastin stains and immunostains for immunoglobulin G4, cluster of differentiation (CD1a), and Langerin were performed. Six comparison cases of RPC in Asian US patients were also examined. Histologic examination of resection specimens revealed markedly dilated large intrahepatic bile ducts with variable degrees of mural fibrosis, periductal gland hyperplasia, inflammation, and liver parenchymal atrophy. These changes were not associated with a ductular reaction. There was no evidence of biliary dysplasia or biliary cirrhosis in any cases. No gross or microscopic feature definitively separated the Asian from non-Asian patients. The etiology of this disorder in non-Asian US patients is unclear. It does not appear to represent a localized variant of Caroli disease or primary sclerosing cholangitis. The high degree of similarity shared by these cases and classic RPC suggests a common pathogenic mechanism, although the pathologic features tend to be less well developed in the cases from the non-Asian US patients.

Common misdiagnoses of biliary atresia

OBJECTIVES

Discrimination of biliary atresia (BA) from other causes of neonatal cholestasis (NC) is challenging. We aimed to analyze the clinicopathological findings in cholestatic infants who were provisionally diagnosed with BA and then excluded by intraoperative cholangiography compared with those with a definitive diagnosis of BA and to shed light on common misdiagnoses of BA.

METHODS

We retrospectively analyzed the data of infants diagnosed preoperatively with BA and referred to surgery between the years 2009 and 2013. On the basis of intraoperative cholangiography results, infants were divided into those with a definitive diagnosis of BA and those misdiagnosed with BA.

RESULTS

Out of 147 infants, there was a misdiagnosis of BA in 10 (6.8%) infants. Alanine transaminase was significantly higher in the non-BA group, whereas other clinical and laboratory findings were comparable in both groups. Hepatomegaly and abnormal gallbladder in ultrasound, and ductular proliferation and advanced grades of portal fibrosis in liver biopsy were significantly higher in infants with BA. However, giant cells were more common in the non-BA infants. Nonetheless, the frequency of clay stool, hepatomegaly, abnormal gallbladder, ductular proliferation, and advanced portal fibrosis was remarkable (100, 70, 40, 70, and 50%, respectively) in the misdiagnosed infants. The misdiagnoses were idiopathic neonatal hepatitis, progressive familial intrahepatic cholestasis type 3, cytomegalovirus hepatitis, Alagille syndrome, and a cholangitic form of congenital hepatic fibrosis.

CONCLUSION

A meticulous preoperative workup should be performed to exclude other causes of NC even if signs of BA are present, especially if features such as giant cells in histopathology are present. This involves completing the NC workup in parallel involving all common causes of NC rather than performing them in series to avoid loss of valuable time and efforts.

Monosegmental hepatobiliary fibropolycystic disease mimicking a mass: report of three cases

Hepatobiliary fibropolycystic diseases are a unique group of entities involving the liver and biliary tract, which are caused by abnormal embryologic development of the ductal plates at various stages. We experienced strange hepatobiliary fibropolycystic diseases with a complex mass composed of malformed ducts and biliary cysts, which did not belong to, and were different from, previously known malformations. They were unique in imaging and histologic features. We herein report three cases of monosegmental hepatobiliary fibropolycystic disease mimicking a mass.

Stroke after percutaneous transhepatic variceal obliteration of esophageal varix in Caroli syndrome

Here we present the case of an 11-year-old female patient diagnosed with Caroli syndrome, who had refractory esophageal varices. The patient had a history of recurrent bleeding from esophageal varices, which was treated with endoscopic variceal ligation thrice over a period of 2 years. However, the bleeding was not controlled. When the patient finally visited the Emergency Department, the hemoglobin level was 4.4 g/dL. Transhepatic intrajugular portosystemic shunt was unsuccessful. Subsequently, the patient underwent percutaneous transhepatic variceal obliteration. Twenty hours after this procedure, the patient complained of aphasia, dizziness, headache, and general weakness. Six hours later, the patient became drowsy and unresponsive to painful stimuli. Lipiodol particles used to embolize the coronary and posterior gastric veins might have passed into the systemic arterial circulation, and they were found to be lodged in the brain, kidney, lung, and stomach. There was no abnormality of the portal vein on portal venography, and blood flow to the azygos vein through the paravertebral and hemiazygos systems was found to drain to the systemic circulation on coronary venography. Contrast echocardiography showed no pulmonary arteriovenous fistula. Symptoms improved with conservative management, and the esophageal varices were found to have improved on esophagogastroduodenoscopy.

Boy with autosomal recessive polycystic kidney and autosomal dominant polycystic liver disease

BACKGROUND

Autosomal recessive polycystic kidney disease (ARPKD) shows a great phenotypic variability between patients, ranging from perinatal demise to mildly affected adults. Autosomal dominant polycystic liver disease (PCLD) does not manifest in childhood.

CASE-DIAGNOSIS/TREATMENT

A boy was reported with the co-occurrence of ARPKD and PCLD. He presented at the age of 16 days with pyelonephritis and urosepsis. Subsequent investigations showed enlarged kidneys and hyperechogenic renal medulla and liver parenchyma. Genetic analysis revealed compound heterozygous mutations in the PKHD1 gene (p.Arg496X and p.Ser1862Leu). After his mother was diagnosed with PCLD, the finding of a liver cyst on ultrasound prompted analysis of the PRKCSH gene, revealing a missense mutation (p.Arg139His). At the most recent follow-up at 13 years of age, the patient's course and clinical examination was uneventful with normal renal and liver function without evidence of portal hypertension.

CONCLUSIONS

The patient with ARPKD and PCLD has so far demonstrated a benign clinical outcome, consistent with the great phenotypic variability of ARPKD and, apart from the liver cyst, asymptomatic manifestation of PCLD in childhood. However, close long-term follow-up is mandatory.

Molecular mechanisms of bile duct development

The mammalian biliary system, consisting of the intrahepatic and extrahepatic bile ducts, is responsible for transporting bile from the liver to the intestine. Bile duct dysfunction, as is seen in some congenital biliary diseases such as Alagille syndrome and biliary atresia, can lead to the accumulation of bile in the liver, preventing the excretion of detoxification products and ultimately leading to liver damage. Bile duct formation requires coordinated cell-cell interactions, resulting in the regulation of cell differentiation and morphogenesis. Multiple signaling molecules and transcription factors have been identified as important regulators of bile duct development. This review summarizes recent progress in the field. Insights gained from studies of the molecular mechanisms of bile duct development have the potential to reveal novel mechanisms of differentiation and morphogenesis in addition to potential targets for therapy of bile duct disorders.

Meckel syndrome with Caroli disease and choledochal cysts

Meckel syndrome is a lethal autosomal recessive disorder characterized by the triad of cystic renal dysplasia, occipital encephalocele, or other anomaly of the central nervous system and post-axial polydactyly. Malformation of the ductal plate is an integral component of Meckel syndrome. Ductal plate malformations include congenital hepatic fibrosis, biliary hamartoma, autosomal dominant polycystic liver disease, Caroli disease, and choledochal cyst. The occurrence of cystic hepatic disease, Caroli disease, and choledochal cyst have not been highlighted. This is a report of a 26-week fetus with features of Meckel syndrome, Caroli disease, and choledochal cyst.

Paediatric chronic liver diseases: how to investigate and follow up? Role of imaging in the diagnosis of fibrosis

Chronic liver diseases are rare in children, but encompass a wide spectrum of disorders that may all be complicated by liver fibrosis and therefore by portal hypertension. They may be classified according to the level of portal flow obstruction: prehepatic, intrahepatic or suprahepatic. Most of them, except presinusoidal diseases, may progress to cirrhosis that carries additional risks of impaired liver function and development of hepatocellular carcinoma. Imaging plays an important role in guiding the diagnosis and biopsy and for follow-up during treatment. US, with high-frequency transducers and Doppler, is the first modality of choice, directs the rest of the investigations and guides interventional radiology. MDCT has made great progress and has replaced angiography for diagnostic purposes. MRI is indicated for parenchyma and nodule characterization and for biliary tract evaluation. To avoid liver biopsy, several elasticity imaging techniques have been developed and have to be evaluated for accuracy and convenience in children. The role of each modality with main imaging findings is described in extrahepatic portal vein obstruction, hepatoportal sclerosis, congenital hepatic fibrosis, cirrhosis and Budd-Chiari syndrome.

Cross-sectional imaging of pediatric biliary disorders

The liver is the largest organ in the abdomen taking up a relatively greater area in infants and young children. It is a unique organ with a dual blood supply and amazing regenerative capacity. The liver has a number of important functions with regard metabolism, detoxification, and immune function. The internal anatomy of this organ is orderly and highly structured around the basic functional unit--the hepatic lobule and portal triad. Numerous pathologic conditions can involve the liver. In this article, we will focus on etiologic, clinical, and cross-sectional imaging features of several childhood congenital and acquired disorders of one component of the portal triad--the biliary system.