Anomalous Pancreaticobiliary Ductal Union Research Articles

Choledochal Cyst with Pancreas Divisum – Surgical Insight into A Rare Association


 
 
 
 Congenital pancreaticobiliary anomalies like pancreatic divisum (PD), choledochal cysts (CDC), anomalous pancreaticobiliary ductal union (APBDU) have been reported in 5.7% of patients undergoing magnetic resonance cholangiopancreatography. CDC’s are characterized by abnormal dilatations of the intrahepatic and/or extrahepatic portion of the biliary tree and can be complicated by cystolithiasis, cholangitis, pancreatitis and malignant transformation necessitating surgical managemnet. While CDCs are commonly associated with APBDU, combination of CDC with PD is rare and a potential surgical challenge. We report a case of recurrent cholangitis in a patient with CDC and coincidental classic PD and illustrate how preoperative identification, fastidious dissection technique to safeguard both the pancreatic ducts and simple intraoperative preemptive strategies may decrease consequences of distal stump blowout. PD, pancreatic divisum; CBD, common bile duct; CDC, choledochal cysts; APBDU, anomalous pancreaticobiliary ductal union; MRCP, magnetic resonance cholangiopancreatography; DOS, Duct of Santorini; DOW, Duct of Wirsung; PTBD, percutaneous transhepatic biliary drainage; RYHJ, roux en Y hepaticojejunostomy.
 
 
 

Biliary Intraepithelial Neoplasia (BilIN) Diagnosed From Choledochal Cyst in 7-Year-Old Girl With Underlying Anomalous Pancreaticobiliary Ductal Union (APBDU)

Biliary Intraepithelial Neoplasia (BilIN) Diagnosed From Choledochal Cyst in 7-Year-Old Girl With Underlying Anomalous Pancreaticobiliary Ductal Union (APBDU)

Clinical comparison between the presence and absence of protein plugs in pediatric choledochal cysts: experience in 390 patients over 30 years in a single center.

PurposeThe incidence of choledochal cyst (CC) with protein plugs is between 15.5%–40.4%. However, studies on CCs with protein plugs in children are limited. We aimed to analyze the clinical features, surgical findings, and complications of pediatric CCs with and without protein plugs.MethodsWe retrospectively analyzed 390 patients who underwent surgery for CCs between January 1987 and September 2017. The patients were divided into 2 groups: groups A (CC with protein plugs) and B (CC without protein plugs). The presence of protein plugs was evaluated using preoperative images or identified during surgery.ResultsOne hundred forty-two (36.4%) patients had protein plugs in the pancreaticobiliary duct. The most common initial clinical presentation was abdominal pain, and its incidence was significantly higher in group A (66.2%) than in group B (54.8%) (P = 0.032). The incidence of accompanying pancreatitis was also significantly higher in group A (37.3% vs. 27.0%) (P = 0.040). Anomalous pancreaticobiliary ductal union (APBDU) was found in 261 patients (66.9%) and its incidence was significantly higher in group A (74.6% vs. 62.5%) (P = 0.014). Most protein plugs were found in the cyst (88.0%) and common channel (31.7%). The incidence of early complications was higher in group A; conversely, that of late complications did not differ.ConclusionApproximately 36.4% of the pediatric CC patients were accompanied by protein plugs. Abdominal pain, pancreatitis, and APBDU were more commonly observed among those with protein plugs than among those without; long-term complications did not differ between them.

Congenital pancreaticobiliary anomalies in an urban medical center in the United States.

Background and AimPancreaticobiliary anomalies are rare and often present with cryptic signs and symptoms, thus delaying appropriate treatment.MethodsEndoscopic retrograde cholangiopancreatography (ERCP) was used to define pancreaticobiliary anomalies. A retrospective review was performed of 5522 ERCPs conducted at a tertiary care center from 1972 to 2015.ResultsThere were 249 (4.5%) patients with pancreaticobiliary anomalies, including 179 patients with pancreas divisum (PD), 44 patients with choledochal cyst (CC) (Todani's classification Type I: extrahepatic cyst 31, Type III; choledochocele 9, Type V: Caroli's disease 4), 20 patients with anomalous pancreaticobiliary ductal union (APDU), and 6 patients with other abnormalities. Of 179 patients with pancreas divisum, 8 (4.5%) required minor sphincterotomies for multiple unexplained acute pancreatitis. Of the 31, 15 (48%) Type I CC patients underwent an operation. In patients with Type III CC (choledochocele), seven of the nine were treated by endoscopic sphincterotomy, and two patients were treated by surgery. Four patients with Type V CC (Caroli's disease) were managed nonoperatively. Of the 20 patients with APDU, 8 (40%) required operative intervention. Six patients were found to have other anomalies: two with pancreas bifidum, one with a duplication of the gallbladder, one with a cystic duct diverticulum, one with an annular pancreas, and one with an abnormal cystic duct origin. These patients were treated based on their etiology.ConclusionPancreaticobiliary anomalies are rare and can be defined using ERCP. The appreciation of these abnormalities is important for the proper diagnosis and treatment of these rare biliary and pancreatic disorders.

Recurrent Acute Pancreatitis with Anomalous Pancreaticobiliary Ductal Union (Komi’s Type IIIc3) with Santorinocele in a Child: A Rare Case Report

ABSTRACTAnomalous pancreaticobiliary ductal union (APBDU) can cause recurrent acute pancreatitis. We describe the case of a 16-year-old boy with recurrent acute pancreatitis. The discussion provides a review of recent literature, supporting use of various diagnostic modalities and surgery as choice of treatment.

Cholangiographic characteristics of common bile duct dilatation in children

To investigate whether children with congenital common bile duct dilatation (CBDD) differ from children with obstructive CBDD in cholangiographic characteristics. In this retrospective cohort study, the baseline data and the results of imaging analyses were reviewed among children who had endoscopic retrograde cholangiopancreatography (ERCP) due to CBDD. ERCP was performed on all pediatric patients by experienced pediatric endoscopists. The maximal transverse diameter of the common bile duct (CBD) was measured on ERCP. To assess whether age-adjusted CBDD could be used for differential diagnosis, a CBDD severity index (SI) was calculated by dividing the measured CBD diameter by the age-corrected maximal diameter of a normal CBD. A retrospective medical chart review revealed that 85 consecutive children under 16 years of age with hepatobiliary disease and CBDD were referred to Seoul Asan Medical Center. Fifty-five (64.7%) children had congenital CBDD and 30 (35.3%) had obstructive CBDD. The two groups did not differ significantly in terms of clinical characteristics except for sex. The congenital and obstructive CBDD groups did not differ significantly in terms of mean CBD diameter (19.3 ± 9.6 mm vs 12.2 ± 4.1 mm, P > 0.05). However, congenital CBDD cases had a significantly higher mean SI than obstructive CBDD cases (3.62 ± 1.64 vs 1.98 ± 0.71, P = 0.01). In multivariate analysis, an SI value ≥ 2.32 and comorbidity with anomalous union of pancreaticobiliary duct (APBDU) in ERCP independently predicted congenital CBDD. Measuring the CBD may aid the differential diagnosis of both CBDD and APBDU in children.

Relationship between Anomalous Pancreaticobiliary Ductal Union and Pathologic Inflammation of Bile Duct in Choledochal Cyst.

PurposeCholedochal cyst is a cystic dilatation of common bile duct. Although the etiology is presently uncertain, anomalous pancreaticobiliary ductal union (APBDU) is thought to be a major etiology of choledochal cyst. In this study, we analyzed the clinical and anatomical characteristics and pathologies of patients diagnosed with choledochal cyst in a single institute for 25 years.MethodsA total of 113 patients, diagnosed with choledochal cyst and who received an operation in Severance Children's Hospital from January 1988 to May 2013, were included. Medical records were reviewed, including clinical and demographic data, surgical procedures. Abdominal ultrasonography, magnetic resonance cholangiopancreatography, and intraoperative cholangiography were used as diagnostic tools for evaluation and classification of choledochal cyst and the presence of anomalous pancreaticobiliary ductal union. Todani's classification, and relationship between APBDU and surgical pathology.ResultsAmong 113 patients, 77 patients (68.1%) presented symptoms such as hepatitis, pancreatitis and/or cholecystitis. Eighty three patients (73.5%) had APBDU, and 94 patients (83.2%) showed inflammatory pathologic changes. APBDU, pathologic inflammation, and serological abnormalities such as hepatitis or pancreatitis showed a statistically significant correlation to one another.ConclusionAPBDU is thought to be one of the etiologic factors of choledochal cyst. It is related to the inflammatory changes in bile duct that can lead to the cystic dilatation.

Prognostic Factors in Patients With Gallbladder Cancer After Surgical Resection

Identification of prognostic factors can help predict life expectancy and decide treatment plan. We evaluated prognostic factors in patients with gallbladder cancer (GBC) after surgical resection. Data from 279 patients with GBC who underwent surgery between January 1999 and February 2009 were reviewed retrospectively. Of the 279 patients, 127 (45.5%) were male; median age was 63 years. R0 resection was achieved in 164 (58.8%) patients, 35 by cholecystectomy and 129 by extended resection. Chemotherapy and radiotherapy were performed in 72 (25.8%) and 55 (19.7%) patients. At a median follow-up of 17.0 months, median overall survival (OS) was 26.0 months. Five-year survival rates for stages I, II, IIIA, IIIB, IVA, and IVB GBC were 94.7%, 75.7%, 44.5%, 21.7%, 4.7%, and 2.6%, respectively. Compared with cholecystectomy, extended resection showed improved OS in all T stages, but statistical significance was observed only in T3 (P<0.001) and T4 (P=0.007). Although OS was similar in patients who received chemotherapy or radiotherapy, radiotherapy significantly improved OS in patients with positive resection margin (P=0.023). Low-grade histologic type (P=0.047) and clear resection margin (P=0.002) were significant predictors of increased OS, but epidemiological factors such as gallstones and anomalous pancreaticobiliary ductal union were not. In patients with GBC after surgical resection, TNM stage was the most important prognostic factor. Prognosis was also associated with extent of resection, histologic differentiation, and involvement of resection margin. In patients with positive resection margin, radiotherapy seems to prolong OS.

Two cases of chronic pancreatitis associated with anomalous pancreaticobiliary ductal union andSPINK1mutation

Chronic pancreatitis is a progressive inflammatory disease resulting from repeated episodes of acute pancreatitis that impair exocrine function and eventually produce endocrine insufficiency. Some causes of chronic pancreatitis appear to be associated with alterations in the serine-protease inhibitor, Kazal type 1 (SPINK1), cationic trypsinogen (PRSS1), and cystic fibrosis-transmembrane conductance regulator (CFTR) genes, or with structural disorders in the pancreaticobiliary ductal system, such as pancreatic divisum or anomalous pancreaticobiliary ductal union (APBDU). However, it is unusual to observe both genetic alteration and structural anomaly. Here, we report 2 cases with both APBDU and a mutation in the SPINK1 genes, and we discuss the implications of these findings in clinical practice.

Gallbladder carcinoma associated with anomalous union of pancreatobiliary ductal system

A 64-year-old woman was admitted with mild right upper quadrant abdominal pain. Her physical examination revealed a moderately nourished female with normal vital sign and no evidence of jaundice or anemia. Preoperative diagnosis was choledochal cyst with anomalous union of pancreaticobiliary duct (AUPBD), long Y-shaped type and gallbladder (GB) cancer. An extended cholecystectomy, excision of the common bile duct and biliary diversion via Roux-en Y hepaticojejunostomy was performed. The gallbladder cancer showed invasion to perimuscular connective tissue and no extension beyond serosa. Twelve months after curative resection, the patient had no evidence of tumor recurrence.

The Relationship Between Biliary Amylase and the Clinical Features of Choledochal Cysts in Pediatric Patients

Although the clinical features of choledochal cysts (CC) in different age groups have been widely studied, the causes of differences in clinical features are unknown. To determine the relationship between biliary amylase and the clinical features of CC in pediatric patients, clinical outcomes were compared in two groups with different amylase levels. From May 1995 to August 2010, 80 patients under 18 years old who underwent choledochal cyst excision and hepaticojejunostomy and measurements of biliary amylase levels were allocated to a low-amylase-level group (amylase level < 200 U/L, n = 26) and a high-amylase-level group (amylase level > 200 U/L, n = 54). Their medical records were retrospectively reviewed. The median age was 4 months (range = 17 days-169 months) in the low group and 48 months (range = 22 days-147 months) in the high group (p = 0.008). In the low group, jaundice was the most common symptom, while abdominal pain was the main symptom in the high group. In histological findings, bile duct proliferation and cholestasis predominated in the low group and portal inflammation predominated in the high group. Radiological findings and preoperative laboratory data were also significantly different between the groups. Postoperative complications occurred in the high group only. There was no mortality in either group. This study shows a relationship between biliary amylase level and clinical manifestations in pediatric patients with CC, implying that there are different underlying pathophysiologies with anomalous pancreaticobiliary ductal union (APBDU).

Choledochal Cyst and Associated Malignant Tumors in Adults

To determine the clinical features and clinical outcomes of Korean adults treated surgically for choledochal cyst. Retrospective nationwide multicenter study. Fifteen university hospitals (tertiary care referral centers) located in all 7 Korean provinces. A total of 808 patients aged 18 years or older who underwent surgery for choledochal cyst from January 1, 1990, through December 31, 2007. Demographic information, surgical data, associated biliary malignant tumors, and factors predicting malignant tumors. Type I was most common (499 [68.2%]) followed by type IVa (208 [28.4%]). Of 654 patients, anomalous pancreaticobiliary ductal union was identified in 467 patients (71.4%), 291 with the choledochal type (62.3%), 96 with the pancreatic type (20.6%), and 80 with the complex type (17.1%). Biliary tract malignant tumor was associated in 80 patients (9.9%); 40 had bile duct cancer (50.0%), 35 had gallbladder cancer (43.8%), 3 had periampullary cancer, and 2 had synchronous gallbladder and bile duct cancer. Twenty-two patients (26.3%) had a recurrence, with a median follow-up duration of 51.8 months. Factors predicting malignant tumor by univariate analysis were age more than 40 years, the absence of a gallstone, elevated carcinoembryonic antigen or cancer antigen 19-9 serum level, and the presence of anomalous pancreaticobiliary ductal union, and by multivariate analysis, an elevated cancer antigen 19-9 level. Associated biliary malignant tumor should always be considered in patients with choledochal cyst, especially in aged patients or patients with anomalous pancreaticobiliary ductal union or an elevated tumor marker level. Lifelong follow-up is needed even after complete cyst excision because of the risk of the development of a metachronous biliary malignant tumor.

Choledochal cyst with ectopic distal location of the papilla of Vater

In cholangiographic techniques, the close relationship between choledochal cyst and anomalous union of pancreaticobiliary duct has attracted medical attention. There have been rare cases in which the papilla of Vater was found in a position other than its normal position, and such cases have been reported sporadically. However, such cases are interesting in the anatomical context. In this review, we present our experience of choledochal cyst in a 30-month-old boy in whom the papilla of Vater was positioned in the third portion of the duodenum.

Synchronous double primary cancers associated with a choledochal cyst and anomalous pancreaticobiliary ductal union

A 60-year-old female was admitted with epigastric pain lasting a month. Preoperative diagnosis was choledochal cyst with anomalous pancreaticobiliaryductal union (APBDU), C-P type. A papillary mass measuring 2.5 × 1.9 cm was found adjacent to the pancreaticocholedochal junction. Gallbladder (GB) cancer was also observed. Pyloric-preserving pancreaticoduodenectomy (PPPD) was performed. The patient received adjuvant chemotherapy/radiation therapy on the tumor bed. The gallbladder cancer showed serosal invasion, while the bile duct cancer extended into the pancreas. Although common bile duct (CBD) cancer lesion showed focally positive for p53 and the gallbladder cancer lesion showed negative for p53, the Ki-67 labeling index of the CBD cancer and GB cancer were about 10% and 30%, respectively. Nine months after curative resection, a stricture on the subhepatic colon developed due to adjuvant radiation therapy. Localized peritoneal seedings were incidentally found during a right hemicolectomy. The patient underwent chemotherapy and had no evidence of tumor recurrence for two years after PPPD.

Clinical comparison of choledochal cysts between children and adults.

Backgrounds/AimsCholedochal cyst of the bile duct is characterized by cystic dilatation of the intra- or extrahepatic bile ducts. It is a relatively uncommon disease and there is still much controversy regarding its etiology as being congenital or acquired.MethodsThe medical records of 60 patients who underwent surgical treatments for choledochal cyst between April 1995 and April 2009 at the Gachon University Gil Hospital were reviewed retrospectively. To compare the clinical characteristics, patients under 19 years of age were grouped into children and the others were grouped into adults.ResultsOf the overall 60 patients, 24 were grouped into children and 36 were grouped into adults. Female predominance was common in both groups (M : F=1 : 6.5). The most common clinical symptom was abdominal pain (73.3%) in both groups. Children had remarkable jaundice (33.3% vs. 0%) and gastrointestinal symptoms including nausea and vomiting. Fever and chills were more common in children because of the associated complications of cholangitis. According to the Todani classification, type I was the most common form of choledochal cyst in both groups, and type IVa was significantly more common in children than adults (45.3% vs. 16.7%). Thirty patients (50%) had anomalous pancreaticobiliary ductal union which was confirmed by preoperative imaging studies or intraoperative cholangiography. All patients except for one child underwent cyst excision with hepaticojejunostomy.ConclusionThere was no significant difference in the clinical characteristics of choledochal cysts between children and adults. However, combined diseases especially bile duct malignancy were common in aged patients, early detection and more aggressive surgery is necessary for patients with choledochal cysts.

Choledochal Cysts: Differences Between Pediatric and Adult Patients

Choledochal cysts in children and adults are believed to be different, but direct comparison between them is lacking in the literature. This study was aimed to identify the clinicopathological differences between 42 children and 59 adults with choledochal cyst treated by same surgeons at the Cathay General Hospital. The mean follow-up period was 8.9 years. The result showed that the female-to-male ratios were 1.5:1 in pediatric patients and 4.9:1 in adult patients. Compared with adults with choledochal cyst, the pediatric patients presented more abdominal mass (52.4% vs 21.2%, P = 0.002) and less abdominal pain (76.2% vs. 98.0%, P = 0.002), are more frequently associated with anomalous pancreaticobiliary ductal union (85.7% vs. 59.6%, P = 0.005) and sudden severe stenosis of terminal choledochus (76.2% vs. 42.3%, P = 0.001), are less commonly associated with choledocholithiasis, are not associated with malignant transformation (0% vs 21.2%), and have fewer perioperative and long-term complications. Nevertheless, patients who received total excision had fewer surgical complications in both groups. This result shows that choledochal cysts in pediatric and adult patients are different in clinicopathological manifestations, prognosis, and the underlying abnormalities of the pancreaticobiliary system, suggesting that patients with choledochal cyst should be managed according to these differences.

Hepatobiliary and Pancreatic: Anomalous union of pancreaticobiliary duct accompanying incomplete type of pancreas divisum

A 16-year old female was referred for further evaluation of long common channel documented on MRCP. Five months ago, she developed colicky pain and fever. Blood chemistry showed these results—AST 185 IU/L, ALT 256 IU/L, alkaline phosphatase 378 U/L, gamma glutamyl transpeptidase 397 U/L, total bilirubin 2.4 mg/dL, and direct bilirubin 1.8 mg/dL. Several tiny stones at the distal common bile duct were observed on CT and were removed completely under ERCP. Four months later, she developed upper abdominal pain and had an amylase level of 1536 IU/L. A CT scan showed pancreatic swelling and peripancreatic infiltration, suggesting acute pancreatitis. She recovered after 4 days of supportive care. A retrospective review of the MRCP revealed a 33 mm-long common channel (Fig. 1, double arrow), prominent Santorini's duct crossing common bile duct, and a short communicating duct (Fig. 1 arrow) between common channel and Santorini's duct (Fig. 1). These findings were documented on the ERCP. There was no abnormal finding suggesting gallbladder cancer or choledochal cyst. The final diagnosis was made as AUPBD with incomplete type of pancreas divisum. MRCP showed 33 mm-long common channel (double arrow), prominent Santorini's duct crossing common bile duct, and a short communicating duct (arrow) between common channel and Santorini's duct. AUPBD is a congenital anomaly, characterized by a junction of the bile duct and pancreatic duct outside of the duodenal wall. It was hypothesized that AUPBD develops as a result of a mis-arrangement of the pancreaticobiliary system. On the other hand, pancreas divisum results from an abnormal fusion of the dorsal and ventral pancreas in utero. Co-incidence of both developmental anomalies may be possible, but the exact incidence rate has not yet been reported. AUPBD and pancreas divisum were observed in up to 1.5% and 7.5% of patients undergoing ERCP respectively. Correct identification and classification of these anomalies can predict clinical manifestations and prognosis so a treatment plan can be made. Gallbladder or bile duct cancer may develop in 15-20% of patients with AUPBD, and recurrent pancreatitis may result from both AUPBD and pancreas divisum. The patient in this case recieved minor papilla intervention with sphincterotomy and stent placement was performed to improve pancreatic flow via Santorini's duct and prevent recurrent pancreatitis (Fig. 2). Surgical therapy may be required at some point in her life, and when and how her pancreaticobiliary duct is to be reconstructed will be an important issue. Considering the patient's young age and second episode of consequent complications, surgical therapy is postponed until recurrent episodes of complications become intractable by endoscopic intervention. Minor papilla intervention with sphincterotomy and stent placement were performed to improve pancreatic flow via Santorini's duct. Contributed by

Adenosquamous carcinoma in a congenital choledochal cyst associated with pancreatico‐biliary maljunction

Congenital choledochal cyst is occasionally complicated by carcinomatous transformation, mostly adenocarcinoma. Adenosquamous carcinoma arising in a congenital choledochal cyst is very rare. The author herein reports an adenosquamous carcinoma arising in congenital choledochal cyst associated with pancreatico-biliary maljunction. A 34-year-old man with congenital choledochal cyst and recurrent cholangitis had been followed up, and was admitted to hospital to undergo testing for cancer. Imaging modalities including computed tomography, magnetic resonance imaging and endoscopic retrograde cholangiography showed an elevated lesion in the choledochal cyst. Because clinical cytology of bile indicated malignant cells, pancreatico-duodenectomy, cholecystectomy, and resection of the choledochal cyst were performed. Grossly, the choledochal cyst was type I, and its size was 8 x 10 cm. Anomalous pancreatico-biliary ductal union was recognized. An elevated lesion was recognized in the choledochal cyst. Histologically, the lesion was composed of a squamous cell carcinoma element and an adenocarcinoma element; a gradual transition was recognized between the two. The squamous cell carcinoma element contained microcytic cells with mucins. On immunohistochemistry the adenocarcinoma element and microcytic cells were positive for CEA, but the squamous cell carcinoma element was negative for CEA. Both elements were positive for CA19-9. Ki-67 labeling was 53% in the adenocarcinoma element and 48% in the squamous cell carcinoma element. p53 protein was negative in both elements. At the time of writing, the patient was alive after 25 months without recurrence or metastasis. The present case is the second case of adenosquamous carcinoma arising in congenital choledochal cyst in the English-language literature.

Endoscopic Treatment of a Pediatric Patient with Acute Pancreatitis Caused by Anomalous Union of Pancreaticobiliary Duct Combined with Incomplete Pancreatic Divisum

The most common causes of acute pancreatitis are microlithiasis and alcohol. In pediatrics, anomalies in pancreaticobiliary system should be considered as possible causes. Among many anomalies, pancreas divisum associated with anomalous pancreaticobiliary ductal union (APBDU) is very rare. APBDU is associated with acute pancreatitis, choledochal cyst, and gallbladder cancer. Pancreas divisum is also a well known cause of acute recurrent pancreatitis. In adult cases with such conditions, the role of endoscopic management including sphincterotomy or stenting through the Santorini duct is well documented. However, it is still controversial to perform endoscopic retrograde cholangiopancreatography in pediatrics. Herein, we experienced a case of 4 year 7 month old female patient suffered from recurrent attacks of acute pancreatitis, which were caused by APBDU and incomplete pancreas divisum. She was treated by endoscopic sphincterectomy of both openings to the Santorinis and Wirsungs ducts. Thus, we report this interesting case with literature review.

A Case of Early Bile Duct Cancer Arising from Villous Adenoma in Choledochal Cyst

Choledochal cyst is an uncommon premalignant anomaly. The morphology and pathogenesis of the premalignant lesion of cholangiocarcinoma arising from the choledochal cyst has not been well described. Herein, we report a rare case of bile duct adenoma arising from choledochal cyst with anomalous union of pancreaticobiliary duct (AUPBD). 50-year-old woman was admitted to our hospital with the complaint of epigastric pain. She had received common bile duct (CBD) exploration and choledocholithotomy and cholecystectomy 3 months earlier under the diagnosis of multiple CBD stones. Intraoperalive cholangiogram was not remarkable except CBD dilatation at that time. Endoscopic retrograde cholangiopancreatography revealed choledochal cyst with AUPBD and round filling defect which disappeared easily on the balloon cholaniogram. On magnetic resonance cholangiopancreatography, the filling defect was confirmed as 2 cm polypoid mass attached to the distal bile duct wall. At laparotomy, a soft whitish mass was palpable on the lower CBD. On histological examination, adenoma with focal carcinoma change arising from choledochal cyst was diagnosed.