Intestinal metaplasia in gallbladder correlates with high amylase levels in bile in patients with a morphologically normal pancreaticobiliary duct

Characterization of gallbladder stones associated with occult pancreaticobiliary reflux using computed tomography

BACKGROUND

Occult pancreaticobiliary reflux (OPBR) is characterized by the absence of congenital anomalies at the pancreaticobiliary junction yet leads to altered bile composition and an increased incidence of gallbladder stones.

AIM

To explore the computed tomography (CT) imaging characteristics of gallbladder stones in patients diagnosed with OPBR.

METHODS

We analyzed 362 patients undergoing cholecystectomy (November 2020 to January 2022). Intraoperative bile samples were assayed for amylase (> 110 U/L indicated OPBR). CT features, including stone density and visibility, were compared between 54 OPBR and 308 controls. Stone attenuation (HU) was measured under standardized conditions (uCT-780, 120 kVp, 160 mAs). Logistic regression and receiver operating characteristic curve analysis identified independent OPBR predictors, forming a validated nomogram.

RESULTS

OPBR patients exhibited significantly higher rates of CT-invisible stones (35.2% vs 12.3%) and uniform stones (87% vs 73.1%) along with lower overall stone density (P = 0.01). Logistic regression identified stone visibility, uniformity, and density as independent predictors. A nomogram integrating these features with patient age achieved high diagnostic accuracy (area under the curve = 0.71).

CONCLUSION

CT imaging distinctly identifies gallbladder stone density, indicating a heightened risk of OPBR in patients with uniform and CT-invisible stones. Such imaging is crucial for preoperative assessments to evaluate potential recurrent biliary pathologies post-cholecystectomy.

Genome-Wide Association Study of Gallstone Disease Identifies Novel Candidate Genomic Variants in a Latino Community of Southwest USA

Gallstone disease (GSD) is a prevalent health condition that impacts many adults and is associated with presence of stones in gallbladder cavity that results in inflammation, pain, fever, nausea and vomiting. Several genome-wide association studies (GWAS) in the past have identified genes associated with GSD but only a few were focused on Latino population. To identify genetic risk factors for GSD in Latino population living in the Southwest USA we used self-reported clinical history, physical and lab measurements data in Sangre Por Salud (SPS) cohort and identified participants with and without diagnosis of GSD. We performed a GWAS on this phenotype using GSD cases matched to normal controls based on a tight criterion. We identified several novel loci associated with GSD as well as loci that were previously identified in past GWAS studies. The top 3 loci (MATN2, GPRIN3, GPC6) were strongly associated with GSD phenotype in our combined analysis and a sex stratified analysis results in females were closest to the overall results reflecting a general higher disease prevalence in females. The top identified variants in MATN2, GPRIN3, and GPC6 remain unchanged after local ancestry adjustment in SPS Latino population. Follow-up pathway enrichment analysis suggests enrichment of GO terms that are associated with immunological pathways; enzymatic processes in gallbladder, liver, and gastrointestinal tract; and GSD pathology. Our findings suggest an initial starting point towards better and deeper understanding of differences in gallstone disease pathology, biological mechanisms, and disease progression among Southwest US Latino population.

Pancreatobiliary reflux increases macrophage-secreted IL-8 and activates the PI3K/NFκB pathway to promote cholangiocarcinoma progression

BACKGROUND

Persistent pancreaticobiliary reflux (PBR) is associated with a high risk of biliary malignancy. This study aimed to evaluate the proportion of PBR in biliary tract diseases and mechanisms by which PBR promoted cholangiocarcinoma progression.

METHODS

Overall 227 consecutive patients with primary biliary tract disease participated in this study. The amylase levels in the collected bile were analyzed. The mechanisms underlying the effect of high-amylase bile on bile duct epithelial and cholangiocarcinoma cells progression were analyzed. The source of interleukin-8 (IL-8) and its effects on the biological functions of cholangiocarcinoma cells were investigated.

RESULTS

The bile amylase levels in 148 of 227 patients were higher than the upper serum amylase limit of 135 IU/L. PBR was significantly correlated with sex, pyrexia, and serum gamma-glutamyl transferase (GGT) levels in the patient cohort. High-amylase bile-induced DNA damage and genetic differences in the transcript levels of the gallbladder mucosa and facilitated the proliferation and migration of bile duct cancer cells (HUCCT1 and QBC939 cells). The concentration of many cytokines increased in high-amylase bile. IL-8 is secreted primarily by macrophages via the mitogen-activated protein kinase pathway and partially by bile duct epithelial cells. IL-8 promotes the progression of HUCCT1 and QBC939 cells by regulating the expression of epithelial-mesenchymal transition-associated proteins and activating the phosphatidylinositol 3-kinase/nuclear factor kappa-B pathway.

CONCLUSIONS

PBR is one of the primary causes of biliary disease. IL-8 secreted by macrophages or bile duct epithelial cells stimulated by high-amylase bile promotes cholangiocarcinoma progression.

Occult pancreaticobiliary reflux is a pathogenic factor of some benign biliary diseases and gallbladder cancer

BACKGROUND

Pancreaticobiliary maljunction (PBM) is a well-known high-risk factor for biliary malignant tumors because of constant pancreaticobiliary reflux (PBR). However, the impact of occult pancreaticobiliary reflux (OPR), which is characterized by high bile amylase levels in individuals with anatomically normal pancreaticobiliary junction, on biliary diseases remains unclear. The aim of this study was to assess the correlation between OPR and biliary diseases.

METHODS

We enrolled 94 consecutive patients with normal pancreaticobiliary junction and primary biliary diseases confirmed by magnetic resonance cholangiopancreatography. We prospectively collected patients' bile samples and measured bile amylase levels. We investigated the incidence of OPR and the difference in bile amylase levels among these patients and assessed the correlation between high bile amylase levels (HBAL) and benign or malignant biliary diseases, as well as the OPR risk factors.

RESULTS

The incidence of OPR was 36.6% in patients with benign biliary diseases, 26.7% in those with cholangiocarcinoma and 62.5% in those with gallbladder cancer. The median bile amylase level tended to be higher in patients with gallbladder cancer than in those with benign biliary diseases, but there was no significant difference (165.5 IU/L vs. 23.0 IU/L, P = 0.212). The prevalence of an HBAL with bile amylase levels of 1000-7500 IU/L was similar in patients with gallbladder cancer and benign biliary diseases. However, the incidence of HBAL with bile amylase levels greater than 7500 IU/L was significantly higher in patients with gallbladder cancer than in those with benign biliary diseases (37.5% vs. 4.2%, P = 0.012). Multivariate logistic regression analysis revealed that choledocholithiasis was an independent risk factor for OPR.

CONCLUSIONS

OPR can occur in benign and malignant biliary diseases, and it may be a pathogenic factor for some benign biliary diseases and a high-risk factor for gallbladder cancer. There is a correlation between choledocholithiasis and OPR.

Free fatty acids and triglyceride change in the gallbladder bile of gallstone patients with pancreaticobiliary reflux

Background

Pancreaticobiliary reflux (PBR) causes chronic inflammation of the gallbladder mucosa and changes in the bile components, which are known to promote gallstone formation. This study aimed to investigate the bile biochemistry changes in gallstone patients with PBR and provide new clues for research on the involvement of PBR in gallstone formation.

Methods

Patients undergoing surgery for gallstones between December 2020 and May 2021 were eligible for inclusion. The bile biochemistry (including amylase, lipase, triglyceride, cholesterol, free fatty acids [FFAs], alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], and γ-glutamyl transferase [γ-GT]) of the included gallstone patients was analysed to determine correlations with PBR.

Results

In this study, 144 gallstone patients who underwent surgery were enrolled. Overall, 15.97 % of the patients had an increased bile amylase level, which was associated with older age and significantly higher bile levels of ALP, lipase, triglyceride, and FFAs. Positive correlations were observed between amylase and lipase, triglyceride, FFAs levels in the gallbladder bile. However, the bile levels of triglyceride, FFAs, and lipase were positively correlated with each other only in the PBR group and showed no significant correlation in the control (N) group. In addition, elevated bile FFAs levels were found to be an independent risk factor for gallbladder wall thickening.

Conclusions

In conclusion, PBR-induced increase in FFAs and triglyceride in the gallbladder bile is a cause of gallstone formation, and an increase in bile ALP suggests the presence of cholestasis in PBR.

Colorectal metastasis to the gallbladder mimicking a primary gallbladder malignancy: histopathological and molecular characteristics

AIMS

Outcomes of colorectal cancer (CRC) treatment and survival have steadily improved during the past decades, accompanied by an increased risk of developing second primary tumours and metastatic tumours at unusual sites. Metastatic CRC can show mucosal colonisation, thereby mimicking a second primary tumour. This potential confusion could lead to incorrect diagnosis and consequently inadequate treatment of the patient. The aim of this study was to differentiate between metastatic CRC and a second primary (gallbladder cancer, GBC) using a combination of standard histopathology and molecular techniques.

METHODS AND RESULTS

Ten consecutive patients with both CRC and GBC were identified in our region using the Dutch National Pathology Archive (PALGA). Two patients served as negative controls. Histology of GBC was reviewed by nine pathologists. A combination of immunohistochemistry, microsatellite analysis, genomewide DNA copy number analysis and targeted somatic mutation analysis was used to aid in differential diagnosis. In two patients, CRC and GBC were clonally related, as confirmed by somatic mutation analysis. For one case, this was confirmed by genomewide DNA copy number analysis. However, in both cases, pathologists initially considered the GBC as a second primary tumour.

CONCLUSIONS

Metastatic CRC displaying mucosal colonisation is often misinterpreted as a second primary tumour. A combination of traditional histopathology and molecular techniques improves this interpretation, and lowers the risk of inadequate treatment.

Gallbladder mucosal lesions associated with high biliary amylase irrespective of pancreaticobiliary maljunction

BACKGROUND

Previous studies have focused on the presence of reflux in selected cohorts with pancreaticobiliary maljunction (PBM), but little is known regarding the wider incidence of occult reflux and associated mucosal changes. We aimed to correlate gallbladder mucosal abnormalities with objective evidence of PBM and occult pancreaticobiliary reflux (PBR) in an Australian population undergoing cholecystectomy.

METHODS

Patients undergoing cholecystectomy between September 2010 and September 2012 were eligible for inclusion. Demographic and pre-operative clinical data were collated and entered into a pre-defined database. Operative cholangiograms were routinely performed and the presence of PBM noted. Gallbladder bile samples were analysed for bilirubin (<20 µmol/L), amylase (<100 U/L) and lipase (<70 U/L) levels. Evidence of PBR was correlated with gallbladder mucosal findings.

RESULTS

A total of 305 cholecystectomies were performed for biliary colic (73%), choledocholithiasis (9%), cholecystitis (8.4%) and pancreatitis (6.4%). A total of 12.7% had cholangiographic evidence of PBM and 11.9% possessed gallbladder mucosal changes. Overall, 7.7% had increased biliary amylase, which was associated with significantly higher rates of gallbladder intestinal metaplasia (33% versus 8.6%; P = 0.012). Elevated biliary amylase was also higher in patients with prior pancreatitis (P = 0.02) or choledocholithiasis (P < 0.01). The presence of PBM did not predict for the presence of PBR.

CONCLUSION

PBR is associated with an increased frequency of gallbladder mucosal metaplasia, irrespective of the presence of PBM. Objectively identified reflux represents an additional indication for cholecystectomy but the long-term consequences for extra-hepatic biliary malignancy remain unknown and warrant further investigation. Methods of objectively identifying PBR pre-operatively require further investigation.

Common bile duct stones associated with pancreatobiliary reflux and disproportionate bile duct dilatation

Occult pancreatobiliary reflux (PBR) in patients with a normal pancreatobiliary junction has been studied by various methods, but the exact etiology, mechanisms, and implications of this reflux have not yet been clarified. The aim of this study was to investigate the degree of PBR and patterns of biliary ductal dilatation in patients with acute calculous cholangitis by endoscopic retrograde cholangiopancreatography (ERCP).We retrospectively evaluated the degree of PBR and pattern of bile duct dilatation in patients with acute calculous cholangitis due to distal CBD (common bile duct) stones (Group A) as compared with patients with malignant CBD obstruction due to distal CBD cancer (Group B). All related data were prospectively collected. Bile juice was aspirated at the proximal CBD for measurement of biliary amylase and lipase before the injection of contrast dye. The diameters of the CBD and the peripheral intrahepatic duct (IHD) were calculated after contrast dye injection. Patients with pancreatobiliary maljunction and/or gallstone pancreatitis were excluded from the study.ERCP was performed on 33 patients with calculous cholangitis (Group A) and 12 patients with malignant CBD obstruction (Group B). Mean levels of bile amylase and lipase were significantly higher (P < .05) in group A (1387 and 6737 U/l, respectively) versus those in group B (32 and 138 U/l, respectively). Thirty patients in group A (90.9%) showed disproportionate dilatation (i.e., CBD was and IHD was not dilated), whereas only 4 patients in group B (33%) showed disproportionate dilatation.The results of this study suggest that patients with calculous cholangitis exhibit PBR that is associated with disproportionate bile duct dilatation.

Elevated bile amylase level without pancreaticobiliary maljunction is a risk factor for gallbladder carcinoma

BACKGROUND

Elevated bile amylase level in patients with pancreaticobiliary maljunction (PBM) or high confluence of pancreaticobiliary ducts (HCPBD) is well known as a risk factor for gallbladder carcinoma (GBC) development. However, the effects of occult pancreaticobiliary reflux (OPR), a condition characterized by high bile amylase level in the presence of an anatomically normal pancreaticobiliary junction, on GBC development remain unclear. The aim of this study was to assess the relationship between OPR and GBC.

METHODS

Clinicopathological data of 52 patients who were preoperatively diagnosed with gallbladder (GB) tumor (22 malignant, 30 benign) were retrospectively reviewed. All of the patients underwent preoperative endoscopic retrograde cholangiopancreatography to evaluate pancreaticobiliary junction morphology and bile amylase level. The relationship between the histological diagnosis of GB lesions, and pancreaticobiliary junction morphology and bile amylase level were investigated.

RESULTS

Pancreaticobiliary maljunction, HCPBD, and normal pancreaticobiliary junction (NPJ) were identified in 12, nine, and 31 patients, respectively. The rates of GBC in patients with PBM, HCPBD, and NPJ were 58% (7/12), 67% (6/9), and 29% (9/31), respectively. Of the 31 patients with NPJ, 22 had OPR and nine of these had GBC. None of the patients with NPJ and normal bile amylase level had GBC. Additionally, among patients with NPJ, bile amylase level was significantly higher in patients with GBC than in patients with benign tumors.

CONCLUSIONS

Occult pancreaticobiliary reflux, like PBM and HCPBD, is a risk factor for GBC development.

Clinicopathologic Differences in Patients with Gallbladder Cancer According to the Presence of Anomalous Biliopancreatic Junction

BACKGROUND

Anomalous biliopancreatic junction (ABPJ) is a risk factor for gallbladder cancer (GBC). This study investigated the significance of ABPJ in patients with GBC.

METHODS

Of the 453 patients with GBC underwent surgery at Seoul National University Hospital between 2000 and 2014, the 401 patients who can be assessed for the presence of ABPJ with radiologic image were analyzed.

RESULTS

The 401 patients with GBC included 183 (45.6 %) males and 218 (54.4 %) females. ABPJ was identified in 69 (17.2 %) patients, 22 (31.9 %) males and 47 (68.1 %) females. Choledochal cyst (CC) was identified in 18 (4.5 %) patients, all of whom had ABPJ. Curative surgery was accomplished in 68.1 %. A comparison of patients with and without ABPJ showed that mean age (59.9 vs. 65.1 years, p < 0.001) and association with gallbladder stone (8.7 vs. 24.7 %, p = 0.002) were significantly lower in the ABPJ group, while the proportion of female (68.1 vs. 51.5 %, p = 0.012), bile duct resection rate (47.8 vs. 18.4 %, p < 0.001), and curative resection rate (81.1 vs. 65.7 %, p = 0.003) were significantly higher in the ABPJ group. Overall 5-year survival rates were similar in the ABPJ and non-ABPJ groups (74.4 vs. 69.0 %, p = 0.533). In patients with ABPJ, the presence of CC did not have a significant effect on survival (p = 0.099).

CONCLUSIONS

ABPJ was found in 17.2 % of patients with GBC. ABPJ is associated with younger age, female gender, absence of gallbladder stones, higher BDR rate, and higher curative resection rate. However, neither ABPJ nor CC was prognostic of survival in curatively treated patients with GBC.

Clinical significance of bile reflux into the pancreatic duct without pancreaticobiliary maljunction assessed by intraoperative cholangiography

INTRODUCTION

Bile reflux into the pancreatic duct (BRPD) is sometimes demonstrated during intraoperative cholangiography (IOC) even in patients without pancreaticobiliary maljunction. However, the clinical significance of this finding in laparoscopic and open cholecystectomy is unclear.

METHODS

Among 484 patients who underwent cholecystectomy (372 laparoscopic, 112 open), patients whose pancreatic duct was depicted in IOC were selected. The value of pancreatic amylase (p-amylase) of the gallbladder bile, histological changes, and the immunohistochemical expression of proliferating cell nuclear antigen (PCNA) in the gallbladder mucosa were analyzed in patients with BRPD. The data were then compared to those in patients without BRPD whose gallbladder bile p-amylase was measured (control group, n = 20).

RESULTS

The success rate of IOC was 93.6%. The rate of BRPD in laparoscopic and open cholecystectomy was 5.2% and 5.7%, respectively. The value of gallbladder bile p-amylase in patients with BRPD was significantly higher than in the control group (790.5 vs 14.0 IU/L, P = 0.034). The value of the PCNA labeling index in patients with BRPD was significantly higher than that of the control group (15.4% vs 4.1%, P = 0.0026). Among the 24 patients with BRPD, pathological changes in the gallbladder mucosa were detected in five (two hyperplasia, three metaplasia), but there was no correlation between the presence of pathological change and PCNA labeling index or gallbladder bile p-amylase.

CONCLUSIONS

IOC could detect BRPD both in laparoscopic and open cholecystectomy at a similar rate. Patients with BRPD had high levels of gallbladder bile p-amylase and PCNA labeling index, findings similar to those in patients with pancreaticobiliary maljunction.

Pancreaticobiliary reflux as a high-risk factor for biliary malignancy: Clinical features and diagnostic advancements

Pancreaticobiliary junction is composed of complex structure with which biliary duct and pancreatic duct assemble and go out into the ampulla of Vater during duodenum wall surrounding the sphincter of Oddi. Although the sphincter of Oddi functionally prevents the reflux of pancreatic juice, pancreaticobiliary reflux (PBR) occurs when function of the sphincter of Oddi halt. The anatomically abnormal junction is termed pancreaticobiliary maljunction (PBM) and is characterized by pancreatic and bile ducts joining outside of the duodenal wall. PBM is an important anatomical finding because many studies have revealed that biliary malignancies are related due to the carcinogenetic effect of the pancreatic back flow on the biliary mucosa. On the other hand, several studies have been published on the reflux of pancreatic juice into the bile duct without morphological PBM, and the correlation of such cases with biliary diseases, especially biliary malignancies, is drawing considerable attention. Although it has long been possible to diagnose PBM by various imaging modalities, PBR without PBM has remained difficult to assess. Therefore, the pathological features of PBR without PBM have not been yet fully elucidated. Lately, a new method of diagnosing PBR without PBM has appeared, and the features of PBR without PBM should soon be better understood.

SOX9 Is Highly Expressed in Nonampullary Duodenal Adenoma and Adenocarcinoma in Humans

BACKGROUND/AIMS

SOX9 is a marker for stem cells in the intestine, and overexpression of SOX9 is found in gastric and colon cancer; however, the expression of SOX9 in nonampullary duodenal adenoma and adenocarcinoma has not yet been evaluated. This study aimed to investigate SOX9 expression in nonampullary duodenal adenoma and adenocarcinoma by immunohistochemistry.

METHODS

We evaluated SOX9 expression in 43 clinical samples (nonampullary duodenal adenoma in 22 lesions and nonampullary duodenal adenocarcinoma in 21 lesions) resected under endoscopic mucosal resection or endoscopic submucosal dissection.

RESULTS

SOX9 was expressed in part of the base of the normal duodenal mucosa surrounding adenomas and adenocarcinomas. In contrast, SOX9-positive cells were found in more than half of the crypts from the bottom part of the crypt in all of the 43 samples. Moreover, in 15 adenoma samples (68.2%) and 19 carcinoma samples (90.5%), SOX9 was expressed in more than three-quarters of the crypts from the bottom part of the crypt.

CONCLUSIONS

SOX9 is overexpressed in nonampullary duodenal adenoma and adenocarcinoma in humans.

Long-term follow-up may be needed for pancreaticobiliary reflux in healthy adults

PURPOSE

The reflux of pancreatic enzymes into the biliary tract is associated with chronic inflammation and increases cellular proliferation of the biliary epithelium, leading to biliary carcinoma. The aim of this study is to detect the incidence of occult pancreaticobiliary reflux (OPBR) in patients who underwent elective cholecystectomy.

METHODS

Forty-seven patients with symptomatic gallstones who underwent cholecystectomy were recruited for this study. The gallbladder bile samples were obtained from the specimen of gallbladder and the amylase level was measured. The immunohistochemistry of p53, SMAD4 and Ki-67 were performed for the detection of metaplasia and dysplasia.

RESULTS

Biliary amylase was higher than the serum amylase in 10 patients (group A, 15,402.66 ± 33,592.43 IU/L; group B, 13.06 ± 18.12 IU/L). The mean age was 67.2 years in group A and 51.2 in group B (P < 0.01). The ratio of male to female was 1:2.3 and 1:1.8 in group A and B, respectively (P = 0.297). Eight patients in group A and thirteen patients in group B had inflammation (P = 0.014). The positive results of the Ki-67 test were exhibited in five cases in each group (P = 0.024).

CONCLUSION

Results from the study indicate that the age was older, degree of inflammation and positive rate of Ki-67 were higher when OPBR was suspected. In conclusion, the patients with OPBR would need long-term follow-up, because the OPBR can cause dysplasia and the reflux of pancreatic juice may be considered as a risk factor for extrahepatic bile duct carcinoma.

Japanese clinical practice guidelines for pancreaticobiliary maljunction

There have been no clinical guidelines for the management of pancreaticobiliary maljunction (PBM). The Japanese Study Group on Pancreaticobiliary Maljunction (JSPBM) has proposed to establish clinical practice guidelines on how to deal with PBM, with the support of the Japan Biliary Association (JBA). Because the body of evidence-based literature is relatively small, we decided to create guidelines based on the consensus of experts, using the medical literature for reference. A total of 46 clinical questions (CQs) were considered by the members of the editorial committee responsible for the guidelines. The CQs covered distinct aspects of PBM: (1) Concepts and Pathophysiology (10 CQs); (2) Diagnosis (10 CQs); (3) Pancreatobiliary complications (9 CQs); and (4) Treatments and prognosis (17 CQs). Statements and comments for each CQ were prepared by the guidelines committee members and collaborating partners. The CQs were completed after review by members of the editorial committee, meetings of this committee, public comments on the homepages of the JSPBM and the JBA, public hearings, and assessment and approval by the guidelines evaluation board. PBM includes cases where the bile duct is dilated (PBM with biliary dilatation) and those in which it is not (PBM without biliary dilatation). In these guidelines, PBM with biliary dilatation is defined as being identical to congenital biliary dilatation of Todani type I (except for type Ib) and type IV-A, both of which are accompanied by PBM in almost all cases. These guidelines are created to provide assistance in the clinical practice of PBM management; their contents focus on clinical utility, and they include general information on PBM to make this disease more widely recognized.

Many faces of pancreaticobiliary reflux

Pancreaticobiliary reflux may occur either as a result of an anatomically abnormal pancreaticobiliary junction or because of a functionally impaired sphincter despite a normal radiological appearance. It is associated with a wide spectrum of biliary diseases, including gall bladder and bile duct carcinoma. Pancreaticobiliary maljunction and related biliary reflux have been studied extensively in Southeast Asian populations and associations with choledochal cyst and biliary malignancy defined. However, reflux in the absence of ductal malunion has only been described relatively recently and its significance with respect to biliary malignancy requires clarification. We present four cases of pancreaticobiliary reflux to demonstrate the varied associations of this under-recognized disorder and review the related management issues.

Current knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and their pathologic implications has experienced tremendous progress during the last few years. This article reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. Many publications with different levels of evidence were found supporting biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. Also, there are many publications supporting the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and sphincter of Oddi dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and their clinical significance, the current evidence does not fully support what has been suggested. The reflux of pancreatic enzymes into the bile tract and gallbladder is a fascinating subject of study which is open to active research. The final demonstration of the pathophysiology and consequences of PBR in NPBL and support by evidence level type I would constitute a major breakthrough in the understanding and eventually in the treatment of gallbladder diseases.

Intestinal phenotypes in pediatric gallbladder epithelium

The aim of this study was to characterize the physiologic expression of "intestinal" features in gallbladders of infants and children. The study group consisted of 56 pediatric (age, 2 weeks to 7 years) and 15 adult (15-25 years) patients who underwent incidental cholecystectomy during surgery for other lesions. All gallbladders examined were histologically unremarkable without inflammation, gallstones, or neoplasia. The presence of goblet cells and the expression of cytokeratin 7, cytokeratin 20, mucin core protein 2, and caudal-related homeobox protein 2 were examined. Intestinal features were frequently detected in the pediatric gallbladders: goblet cells in 34 cases (61%), cytokeratin 20 expression in 25 (45%), mucin core protein 2 expression in 32 (57%), and caudal-related homeobox protein 2 expression in 16 (29%). In contrast, none of these features was identified in adult gallbladders. The expression of mucin core protein 2 was mostly restricted to goblet cells in pediatric gallbladders, whereas cytokeratin 20 and caudal-related homeobox protein 2 were expressed in both goblet and nongoblet cells. Cytokeratin 7 was diffusely and consistently expressed in both pediatric and adult gallbladder epithelium including goblet cells. Intestinal features became less frequent with age and were scarce in children aged 6 to 7 years. Thus, goblet cells were identified in 14 (93%) of 15 children aged <1 year, together with the common expression of cytokeratin 20 (73%), mucin core protein 2 (93%), and caudal-related homeobox protein 2 (53%). In conclusion, intestinal features are physiologically present in gallbladder epithelium of children, particularly those aged <6 years. Intestinal metaplasia, as associated with cholangiopathy or carcinogenesis in adult patients, may represent an immature phenotype of biliary epithelium.

Pancreaticobiliary reflux in patients with a normal pancreaticobiliary junction: Pathologic implications

Knowledge on pancreaticobiliary reflux in normal pancreaticobiliary junction and its pathologic implications has experienced tremendous progress during the last few years. This editorial reviews the current knowledge on this condition and its pathological implications on gallbladder diseases. The following aspects were defined appropriate for discussion: (1) Evidence of carcinogenesis associated with pancreaticobiliary reflux; (2) Evidence of pancreaticobiliary reflux in normal pancreaticobiliary junction; and (3) Evidence of sphincter of Oddi (SO) dysfunction as a cause of pancreaticobiliary reflux in normal pancreaticobiliary junction. The articles reviewed were selected and classified according to five levels of evidence: LevelI, meta-analysis double-blind randomized clinical trials, Level II, cohort non-blinded studies and non-randomized clinical trials, Level III, good quality case-control studies and non-randomized cohort studies, Level IV, case series and poor quality case-control studies, and Level V, case report articles and experts’ opinion. Evidence levels II, III, IV and V were found to support biliary carcinogenesis associated with pancreaticobiliary reflux in normal and abnormal pancreaticobiliary junction. The same levels of evidence were found to support the common occurrence of pancreaticobiliary reflux in normal pancreaticobiliary junction, and SO dysfunction as the most plausible cause of this condition. Although an important body of research has been published regarding pancreaticobiliary reflux in normal pancreaticobiliary junction and its clinical significance, the current evidence does not fully support what has been suggested. Studies with evidence level I have not been undertaken. This is a fascinating subject of study, and if finally supported by evidence level I, the importance of this condition will constitute a major breakthrough in biliary pathology.

Progress in research of occult pancreatobiliary reflux

Increasing knowledge regarding pancreaticobiliary maljunction (PBM) has led researchers to find that pancreatobiliary reflux (flow of pancreatic juice into the biliary tract) occurs not only in PBM patients but also in individuals with a normal pancreaticobiliary junction (occult pancreatobiliary reflux, OPR). The functional disorders of the sphincter of Oddi have been proposed as a possible cause for OPR. Some studies have found that OPR is a high risk factor for gallbladder cancer. The incidence of choledochal stones is higher in patients with OPR than in those without OPR. In this article, we review the progress in research of OPR.