Intraductal papillary mucinous neoplasm involving pancreaticobiliary maljunction and an aberrant pancreatic duct draining into the stomach: A case report and review of the literature

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

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.

Adenocarcinoma with intraductal papillary mucinous neoplasm arising in a duodenal heterotopic pancreas: a case report

A woman in her 70 s was diagnosed with a tumor in her duodenal wall during a routine visit for diabetes. She subsequently underwent subtotal stomach-preserving pancreatoduodenectomy. Histologically, the tumor was present mainly in the duodenal wall, and atypical cystic ducts were seen in the muscularis propria and subserosa. Invasive well-differentiated adenocarcinoma was seen in the duodenal submucosal and mucosal layers. Heterotopic pancreatic tissue was seen within the tumor, and atypical epithelium had proliferated and replaced the cystic ductal epithelium of the heterotopic pancreas. Therefore, adenocarcinoma with intraductal papillary mucinous neoplasm arising in duodenal heterotopic pancreas was the final histopathological diagnosis, which is considered rare.