Caroli's Disease: Current Knowledge of Its Biliary Pathogenesis Obtained from an Orthologous Rat Model

A Rare Case of Caroli's Syndrome

Caroli's syndrome is a rare autosomal recessive congenital disorder of the biliary tree characterized by intrahepatic bile duct dilation and hepatic fibrosis. Very few cases have been encountered in routine day-to-day practice. The patients usually present with features of cholangitis such as pain abdomen and jaundice. They may also present with features of chronic liver disease and portal hypertension. Very rarely, they may develop cholangiocarcinoma and present with jaundice, weight loss, and abdominal mass or ascites. Here, we report one such case of a young female who presented to us with features of cholangitis with sepsis and encephalopathy, which was finally diagnosed as Caroli's syndrome. The aim of presenting this case is to learn that even patients with common symptoms of pain abdomen and jaundice may be harboring some rare congenital disease like Caroli's syndrome, as in our case.

Laparoscopic hepatectomy for the treatment of Caroli's disease: a case report

Caroli disease is a rare congenital disorder characterized by nonobstructive dilatation of intrahepatic ducts. In cases with symptomatic intrahepatic manifestations, treatment should correspond to the type with hepatic resection for localized disease and transplantation for diffuse forms. If possible, complete resection of the cysts can cure the symptoms and avoid the risk of malignancy. A 66-year-old woman presented to Wuxi Xishan People's Hospital with recurrent intermittent upper quadrant abdominal pain. Further examinations suggested the diagnosis of Caroli disease limited to the left hepatic lobe. She underwent laparoscopic hepatectomy. Pathological examination confirmed the diagnosis of Caroli disease, and no malignancy was found. There were no immediate complications and no long-term complications after one and one-half years of follow-up. Laparoscopic hepatectomy could be a feasible, safe treatment option for localized Caroli disease.

Caroli's disease misdiagnosed as intraductal papillary neoplasm of the bile duct

Caroli's disease is a rare autosomal-recessive disorder caused by malformation of the ductal plate during embryonic development. Although it is present at birth, Caroli's disease is typically not diagnosed until between the second and fourth decades of life, as it was in the present patient. Here we report a rare case of Caroli's disease limited to one liver segment, which was initially misdiagnosed as an intraductal papillary neoplasm of the bile duct. The asymptomatic patient was treated with liver segmentectomy.

Clinical classification of Caroli's disease: an analysis of 30 patients

BACKGROUND

Caroli's disease (CD) is a rare congenital disorder. The early diagnosis of the disease and differentiation of types I and II are of extreme importance to patient survival. This study was designed to review and discuss observations in 30 patients with CD and to clarify the clinical characteristics of the disease.

METHODS

The demographic and clinical features, laboratory indicators, imaging findings and pathology results for 30 patients with CD were reviewed retrospectively.

RESULTS

Caroli's disease can occur at any age. The average age of onset in the study cohort was 24 years. Patients who presented with symptoms before the age of 40 years were more likely to develop type II CD. Approximately one-third of patients presented without positive signs at original diagnosis and most of these patients were found to have type I CD on pathology. Anaemia, leucopoenia and thrombocytopoenia were more frequent in patients with type II than type I CD. Magnetic resonance cholangiopancreatography (MRCP) and computed tomography (CT) examinations were most useful in diagnosing CD.

CONCLUSIONS

No typical symptoms, signs or laboratory indicators are able to distinguish CD from other conditions. Both MRCP and CT were most valuable in diagnosis. The two types of CD may be differentiated by age of onset and routine blood tests.

Activation of the PI3K/mTOR pathway is involved in cystic proliferation of cholangiocytes of the PCK rat

The polycystic kidney (PCK) rat is an animal model of Caroli’s disease as well as autosomal recessive polycystic kidney disease (ARPKD). The signaling pathways involving the mammalian target of rapamycin (mTOR) are aberrantly activated in ARPKD. This study investigated the effects of inhibitors for the cell signaling pathways including mTOR on cholangiocyte proliferation of the PCK rat. Cultured PCK cholangiocytes were treated with rapamycin and everolimus [inhibitors of mTOR complex 1 (mTOC1)], LY294002 [an inhibitor of phosphatidylinositol 3-kinase (PI3K)] and NVP-BEZ235 (an inhibitor of PI3K and mTORC1/2), and the cell proliferative activity was determined in relation to autophagy and apoptosis. The expression of phosphorylated (p)-mTOR, p-Akt, and PI3K was increased in PCK cholangiocytes compared to normal cholangiocytes. All inhibitors significantly inhibited the cell proliferative activity of PCK cholangiocytes, where NVP-BEZ235 had the most prominent effect. NVP-BEZ235, but not rapamycin and everolimus, further inhibited biliary cyst formation in the three-dimensional cell culture system. Rapamycin and everolimus induced apoptosis in PCK cholangiocytes, whereas NVP-BEZ235 inhibited cholangiocyte apoptosis. Notably, the autophagic response was significantly induced following the treatment with NVP-BEZ235, but not rapamycin and everolimus. Inhibition of autophagy using siRNA against protein-light chain3 and 3-methyladenine significantly increased the cell proliferative activity of PCK cholangiocytes treated with NVP-BEZ235. In vivo, treatment of the PCK rat with NVP-BEZ235 attenuated cystic dilatation of the intrahepatic bile ducts, whereas renal cyst development was unaffected. These results suggest that the aberrant activation of the PI3K/mTOR pathway is involved in cystic proliferation of cholangiocytes of the PCK rat, and inhibition of the pathway can reduce cholangiocyte proliferation via the mechanism involving apoptosis and/or autophagy.

MALDI imaging MS reveals candidate lipid markers of polycystic kidney disease

Autosomal recessive polycystic kidney disease (ARPKD) is a severe, monogenetically inherited kidney and liver disease. PCK rats carrying the orthologous mutant gene serve as a model of human disease, and alterations in lipid profiles in PCK rats suggest that defined subsets of lipids may be useful as molecular disease markers. Whereas MALDI protein imaging mass spectrometry (IMS) has become a promising tool for disease classification, widely applicable workflows that link MALDI lipid imaging and identification as well as structural characterization of candidate disease-classifying marker lipids are lacking. Here, we combine selective MALDI imaging of sulfated kidney lipids and Fisher discriminant analysis (FDA) of imaging data sets for identification of candidate markers of progressive disease in PCK rats. Our study highlights strong increases in lower mass lipids as main classifiers of cystic disease. Structure determination by high-resolution mass spectrometry identifies these altered lipids as taurine-conjugated bile acids. These sulfated lipids are selectively elevated in the PCK rat model but not in models of related hepatorenal fibrocystic diseases, suggesting that they be molecular markers of the disease and that a combination of MALDI imaging with high-resolution MS methods and Fisher discriminant data analysis may be applicable for lipid marker discovery.

Roles of myofibroblasts and notch and hedgehog signaling pathways in the formation of intrahepatic bile duct lesions in polycystic kidney rats

Polycystic kidney (PCK) rats, an animal model of Caroli's disease, show a dilatation of intrahepatic bile ducts (IHBD) called "ductal plate malformation." Mesenchymal cells and the Notch and Hedgehog signaling pathways in portal tracts are reportedly involved in the normal development of IHBD, although there have been no studies on the roles of these signaling pathways in PCK rats. We immunohistochemically examined the expression of the molecules related to these signaling pathways in portal tracts. All molecules related to these signaling pathways expressed in portal tracts in Sprague Dawley (SD) rats (control) were also expressed in PCK rats. Mesenchymal cells (myofibroblasts) were frequently found in the connective tissue of portal tracts of 20 embryonic-day-old (E20D), 1-day-old (1D), and 1-week-old (1W) SD and PCK rats and were abundant in PCK rats. Interestingly, myofibroblasts almost disappeared at in both strains of 3W rats. Jagged1 was expressed in mesenchymal cells in portal tracts and was abundant in PCK rats. Double immunostaining showed that Jagged1-positive cells were myofibroblasts. Notch2 and HES1 were expressed in cholangiocytes of the bile ducts of both rats. Sonic Hedgehog was similarly expressed in the bile ducts of both rats. A well-balanced and time-sequential expression of the Notch and Hedgehog family in portal tracts might be essential for the normal development of IHBD in E20D to 1W SD rats, and an imbalanced interaction of these molecules, particularly increased Jagged1 expression in periductal and periportal myofibroblasts and Notch2 expressed in cholangiocytes, may be involved in the formation of bile duct lesions in PCK rats.

Invasive biliary mucinous cystic neoplasm: a review

OBJECTIVES

Biliary mucinous cystic neoplasms (BMCNs) are recently redefined rare liver tumours in which insufficient recognition frequently leads to an incorrect initial or delayed diagnosis. A concise review of the subtle, sometimes non-specific, clinical, serologic and radiographic features will allow for a heightened awareness and more comprehensive understanding of these entities.

METHODS

Literature relating to the presentation, diagnosis, treatment, pathology and outcomes of BMCNs and published prior to March 2012 was reviewed.

RESULTS

Biliary mucinous cystic neoplasms most commonly occur in females (≥60%) in the fifth decade of life. Clinical symptoms, serologic markers and imaging modalities are unreliable for diagnosis of BMCNs, which leads to misdiagnosis in 55-100% of patients. Perioperative cyst aspiration is not recommended as invasive BMCNs can only be differentiated from non-invasive BMCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate BMCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis.

CONCLUSIONS

A low threshold for considering BMCN in the differential diagnosis of cystic liver lesions and increased attentiveness to its subtle diagnostic characteristics are imperative. The complete surgical resection of BMCNs and the use of appropriate nomenclature are necessary to improve outcomes and accurately define prognosis.

A complex case of congenital cystic renal disease

This case outlines the potential complexity of autosomal recessive polycystic kidney disease (ARPKD). It highlights the challenges involved in managing this condition, some of the complications faced and areas of uncertainty in the decision making process. With a paucity of published paediatric cases on this subject, this should add to the pool of information currently available.