Using Endoscopic Ultrasound to Confirm an Uncommon Condition

Abstract

Question: A 39-year-old Caucasian man with no past medical history and taking no medications or supplements, was referred to the gastroenterology clinic with jaundice and pruritis for 1 week in addition to increased bloating after an initial visit with his primary care physician. He complained of dark urine and lighter colored stools for the previous 2 weeks in addition to postprandial nausea. There was no history of abdominal pain, vomiting, fevers, significant weight loss, or gastrointestinal bleeding. On physical examination, he was normotensive and afebrile. Sclera were mildly icteric. There was mild tenderness to deep palpation in the right upper quadrant. The rest of the examination was unremarkable. Laboratory data revealed a white blood cell count of 4.5 K/μL, hemoglobin of 14.7 g/dL, lipase of 600 U/L, aspartate aminotransferase of 164 U/L, alanine aminotransferase of 628 U/L, alkaline phosphatase of 487 U/L, and total bilirubin of 5.2 mg/dL. Computed tomography (CT) of the abdomen and pelvis (Figure A) was ordered by his primary care physician and showed pancreatic duct dilatation, intrahepatic and extrahepatic biliary dilatation (common bile duct 16 mm) with an abnormality noted at the level of the distal bile duct (arrow), but no definite evidence of pancreatic neoplasm or biliary stones. Endoscopic ultrasound was performed (Figure B) and demonstrated a 16.8-mm common bile duct (thin arrow), a 5.4-mm pancreatic duct in the head of the pancreas (medium arrow), and a large abnormality of the distal common bile duct, in the duodenal wall (thick arrow). What is the diagnosis? What is a major long-term risk associated with this lesion? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. This patient has a choledochocele, a cystic dilatation of the extrahepatic intraduodenal biliary tree as described by the Todani classification.1Lipsett P.A. Pitt H.A. Surgical treatment of choledochal cysts.J Hepatobiliary Pancreat Surg. 2003; 10: 352-359Crossref PubMed Scopus (111) Google Scholar He underwent endoscopic retrograde cholangiopancreatography (ERCP). Endoscopically, a large, bulbous cyst protruding just above the ampulla was demonstrated (Figure C). Cholangiogram confirmed intrahepatic and extrahepatic biliary dilatation without filling defects or sludge. The cyst was completely unroofed via sphincterotomy (Figure D) with free flow of bile and contrast noted. On follow-up his laboratory values normalized and he became asymptomatic. Choledochal cysts are rare, congenital abnormalities of unclear etiology that have a 4:1 female predominance.2Dabbas N. Davenport M. Congenital choledochal malformation not just a problem for children.Ann R Coll Surg Engl. 2009; 91: 100-105Crossref PubMed Scopus (38) Google Scholar These lesions could be due to a congenital abnormality of the pancreaticobiliary junction with a long common channel allowing reflux of pancreatic juice into the biliary tree or a congenital defect occurring in maturation where the ductal plate is malformed. Others believe they might form postnatally in reaction to environmental factors or inflammation.3Lipsett P.A. Locke J.E. Biliary cystic disease.Curr Treat Options Gastroenterol. 2006; 9: 107-112Crossref PubMed Scopus (5) Google Scholar The incidence in the Americas and Europe is between 1/100,000 to 1/150,000 live births with much higher incidences in Asia.1Lipsett P.A. Pitt H.A. Surgical treatment of choledochal cysts.J Hepatobiliary Pancreat Surg. 2003; 10: 352-359Crossref PubMed Scopus (111) Google Scholar The reported triad of right upper quadrant pain, jaundice, and palpable abdominal mass is rarely identified.1Lipsett P.A. Pitt H.A. Surgical treatment of choledochal cysts.J Hepatobiliary Pancreat Surg. 2003; 10: 352-359Crossref PubMed Scopus (111) Google Scholar, 2Dabbas N. Davenport M. Congenital choledochal malformation not just a problem for children.Ann R Coll Surg Engl. 2009; 91: 100-105Crossref PubMed Scopus (38) Google Scholar ERCP and magnetic resonance cholangiopancreatography are key to defining anatomy. Although controversial, the only type of choledochal cyst that is amenable to endoscopic therapy is a choledochocele.3Lipsett P.A. Locke J.E. Biliary cystic disease.Curr Treat Options Gastroenterol. 2006; 9: 107-112Crossref PubMed Scopus (5) Google Scholar Other cystic lesions frequently require surgery. Malignancy developing in the cyst itself, within the gallbladder, or much less often in the intrahepatic ducts by the third decade is a major long-term risk.2Dabbas N. Davenport M. Congenital choledochal malformation not just a problem for children.Ann R Coll Surg Engl. 2009; 91: 100-105Crossref PubMed Scopus (38) Google Scholar Physicians should consider cholecystectomy and monitor their patients for malignancy.