A case report of gallbladder cancer and pancreas cystic neoplasm associated with pancreaticobiliary maljunction

Abstract

Introduction and importance: Pancreaticobiliary maljunction (PBM) is a rare congenital anomaly that is frequently associated with carcinoma of the biliary tract. However, there is still no clear evidence that PBM is associated with pancreatic tumors. Here we describe a case of gallbladder cancer and intraductal papillary mucinous neoplasm (IPMN) that is associated with PBM.

Case presentation: A 72-year-old man underwent a cholecystectomy with hepatectomy (S4a + S5) and regional lymph node dissection for gallbladder adenocarcinoma invading the front lobe branch of the hepatic artery. A pylorus-preserving pancreaticodudenectomy was also performed for pancreatic IPMN.

Clinical discussion: Presence of mucin type 6 (MUC6) -positive pyloric gland metaplasia in both the dilated pancreatic duct and the gallbladder background mucosa suggests that pancreatic IPMN and gallbladder cancer may have a common phenotypic origin. Additionally, analysis of 41 reported cases of pancreatic cancer associated with PBM revealed that in all metachronous multiple cancer cases, biliary tract cancer preceded the pancreatic cancer with congenital biliary dilatation accompanied by PBM. The analysis also revealed an increased proportion of pancreatic cancer cases with PBM in patients who had not undergone a flow diversion procedure located in pancreatic head.

Conclusion: We show an interesting relationship between pancreatic/gallbladder cancer and PBM. More comprehensive evaluations of the whole pancreaticobiliary system in follow-up of patients with PBM is required to understand the full extent of this relationship.

Keywords: Case report; Gallbladder cancer; Intraductal papillary mucinous neoplasm; Pancreaticobiliary maljunction.

Fig. 1

Preoperative CT and MRI. a-b A horizontal image (a) and a coronal image (b) of an enhanced CT scan showing enhanced wall thickness in the gallbladder (yellow arrow). The common bile duct was dilated up to 43 mm (red arrow). c A MRCP scan showed an anomalous junction of pancreaticobiliary tracts. Both the common bile duct and the intrahepatic bile duct are dilated (yellow arrowhead). The pancreatic uncinate process is occupied by a “bunch of grapes” lesion apart from main pancreatic duct suggesting the branch duct type IPMN (red arrowhead). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Macroscopic findings of the resected specimen. a Mucosal side showed the wall thickness of gallbladder (solid arrow). b Serosal side showed the cystic dilatation of the common bile duct (arrowhead). Pancreatic duct joined the common bile duct approximately 30 mm above the papilla of Vater (white dashed arrow).

Fig. 3

Histopathological examination of pancreas. a Hematoxylin and eosin (H&E) staining for the dilated pancreatic duct at the site of the pancreaticobiliary junction. The magnification of the micrograph is 40×. b Higher magnification (200×) for the circled area of panel a. Atypical changes were detected in the epithelium of the dilated pancreatic duct. c Immunohistochemistry with the anti-MUC6 antibody on the dilated pancreatic duct. The presence of MUC6-immunoreactive cells suggested pyloric gland metaplasia in the atypical pancreatic epithelium. The magnification of the micrograph is 200×.

Fig. 4

Histopathological examination of gallbladder. a Pathological diagnosis of gallbladder cancer was poorly differentiated tubular adenocarcinoma (arrow). The magnification of the micrograph is 40×. b Immunohistochemistry with anti-MUC6 antibody in the gallbladder. The gallbladder cancer lesion was negative for MUC6, whereas MUC6-positive pyloric gland metaplasia was detected in the non-cancerous mucosa of the gallbladder (arrowhead). The magnification of the micrograph is 40×.