Clinical Challenges

Clinical Challenges - May 2016
What's Your Diagnosis?

Publish date: May 28, 2016

By Dr. Katherine Albutt, Dr. Laurence Bailen, and Dr. Carlos Fernandez-del Castillo. Published previously in Gastroenterology (2012;143:896, 1121-2).

A 63-year-old African American woman with a history of recurrent pancreatitis was admitted with severe right upper quadrant pain radiating to the back. Her medical history was notable for three prior episodes of pancreatitis that required hospitalization in 2000, 2006, and 2007.

On the day of admission, physical examination revealed a soft abdomen that was tender to palpation in the right upper quadrant with a positive Murphy’s sign. Laboratory data were notable for an amylase level of 1,203 U/L and a lipase level of 2,091 U/L in the setting of normal liver function tests (LFTs) and a normal leukocyte count. The cancer antigen (CA) 19-9 level at this time was 299 U/mL.

The patient then underwent abdominal sonography and computed tomography (Figure A). Magnetic resonance cholangiopancreatography was also performed (Figure B). Because of rising LFTs, endoscopic retrograde cholangiopancreatography was performed, and a biliary stent was placed. An endoscopic ultrasound was performed at the time of endoscopic retrograde cholangiopancreatography (Figure C).

Once the acute pancreatitis resolved and the patient was tolerating a regular diet, she was discharged home. At this time, the level of CA 19-9 was 35 U/mL. She was subsequently taken to the operating room for a planned pancreaticoduodenectomy, cholecystectomy, and dissection of periportal lymph nodes. The Whipple specimen was removed en bloc with the gallbladder (Figure D).

The patient’s postoperative course was uneventful, and she was discharged home on postoperative day 7. Postoperative laboratory values were notable for a CA 19-9 of 23 U/mL and carcinoembryonic antigen of 3.3 ng/mL. What is the diagnosis?


 

The diagnosis

Figure A shows marked intrahepatic and extrahepatic biliary ductal dilation and an irregular enhancing mass along the lateral wall of the gallbladder (long arrow). Figure B shows an abnormal pancreaticobiliary junction, with the common bile duct inserting into a distal pancreatic duct to form a cystically dilated common channel (arrowhead), as well as a bifid main pancreatic duct (long arrow). Figure C shows a bifid pancreatic duct and no evidence of a pancreatic mass. Other endoscopic ultrasound images visualized an irregular gallbladder mass. Figure D shows an irregular mass in the gallbladder wall, with final pathology revealing an invasive, well-differentiated adenocarcinoma of the gallbladder (long arrow) with negative margins and no evidence of lymph node involvement (T1N0Mx). The final diagnosis was pancreaticobiliary maljunction (PBM) with bifid pancreatic ducts presenting as recurrent pancreatitis and concurrent gallbladder adenocarcinoma.

It is well established that PBM, an anomalous junction of the pancreaticobiliary ductal system, is frequently associated with carcinomas of the biliary tract. First described in 1916 by Kozumi and Kodama, PBM is a rare congenital malformation most prevalent in Asia that is defined as an anomalous junction of the pancreatic and biliary ducts located outside of the duodenal wall. 1PBM often manifests clinically as intermittent abdominal pain, obstructive jaundice, and/or acute pancreatitis, although patients may be asymptomatic. The most concerning problem, however, is the close relationship of biliary tract carcinogenesis to PBM, with gallbladder carcinoma and bile duct cancers arising in 14.8% and 4.9% of patients with PBM, respectively. 2 The anomalous junction is thought to preclude normal sphincter of Oddi function, thus facilitating the reciprocal reflux of bile and pancreatic juice and ultimately leading to biliary carcinogenesis. Tumor markers, such as CA 19-9 and carcinoembryonic antigen, may be of some diagnostic value in PBM and biliary tract neoplasms, although they lack sensitivity and specificity because of significant overlap with benign disease, such as pancreatitis. This particular case had the added novelty of a bifid pancreatic duct. The clinical significance of a bifid pancreatic duct is unclear, and no relationship has been demonstrated between this ductal anomaly and pancreaticobiliary disease. In this case, a pancreaticoduodenectomy with en bloc resection of the gallbladder was performed to resect the gallbladder mass with clear margins and eliminate the risk for further biliary tract carcinogenesis while simultaneously excising the anomalous junction thought to be causing the recurrent pancreatitis.

References

1. Todani T., Arima E., Eto T., et al. Diagnostic criteria of pancreaticobiliary maljunction. J Hepatobiliary Pancreat Surg. 1994;1:219-21.

2. Funabiki T., Matsubara T., Miyakawa S., et al. Pancreaticobiliary maljunction and carcinogenesis to biliary and pancreatic malignancy. Langenbecks Arch Surg. 2009;39:149-69.

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