[Heterotopic pancreatic tissue in the bifurcation of the bile duct : Rare diagnosis mimicking a Klatskin tumour]

Intrahepatic peribiliary perivascular epithelioid cell tumor (PEComa) associated with heterotopic pancreas: A case report

Background

Perivascular epithelioid-cell tumor (PEComa) is a group of rare mesenchymal neoplasms that express myomelanocytic-cell markers and exhibit a wide variety of histopathological features. Although heterotopic pancreas has been reported to occur in the gastrointestinal tract, intrahepatic heterotopic pancreas has been reported only rarely.

Case presentation

We present a case of intrahepatic PEComa that showed a strong regional correlation with the presence of heterotopic pancreas. An intrahepatic tumor and biliary dilatation was incidentally discovered during a diagnostic evaluation to investigate low-back pain in a 47-year-old Japanese male. Cholangiocarcinoma was suspected and a left hemihepatectomy performed. Histological examination revealed a 3 × 3.8-mm tumor in the neighboring B2 bile duct. Histological and immunohistochemical investigations revealed the presence of a PEComa and pancreatic acini within the tumor mass. PEComa in the hepatobiliary and pancreatic regions are extremely rare. The presence of heterotopic pancreas is also relatively uncommon.

Conclusion

The strong regional association of these 2 lesions raises the possibility of a PEComa originating from heterotopic pancreas or from an irritable response caused by heterotopic pancreas.

Klatskin-like lesions

Hilar cholangiocarcinoma, also known as Klatskin tumour, is the commonest type of cholangiocarcinoma. It poses unique problems in the diagnosis and management because of its anatomical location. Curative surgery in the form of major hepatic resection entails significant morbidity. About 5-15% of specimens resected for presumed Klatskin tumour prove not to be cholangiocarcinomas. There are a number of inflammatory, infective, vascular, and other pathologies, which have overlapping clinical and radiological features with a Klatskin tumour, leading to misinterpretation. This paper aims to summarise the features of such Klatskin-like lesions that have been reported in surgical literature.

Adenocarcinoma arising from intrahepatic heterotopic pancreas: A case report and literature review

Heterotopic pancreas is mostly found incidentally, and adenocarcinoma arising from heterotopic pancreas appears to be extremely rare. A case of a 46-year-old woman with adenocarcinoma arising from intrahepatic heterotopic pancreas is reported herein. Computed tomography demonstrated a mass located in the bile duct of the left hepatic lobe. Pathological examination revealed a moderately differentiated adenocarcinoma arising from intrahepatic heterotopic pancreas with nerve infiltration. This may be the first reported case of adenocarcinoma arising from intrahepatic heterotopic pancreas.

Heterotopic pancreas causing duodenal obstruction in a patient previously treated for choledochal cyst

A 9-year-old boy presented with duodenal pancreatic rest causing obstruction and required surgical intervention. He had been treated at the age of 4 months for a choledochal cyst. Both choledochal cyst and heterotopic pancreas are entities that are commonly encountered in children, but the incidental presence of both the entities in the same child, albeit presenting metachronously, is extremely rare.

Heterotopic pancreatic tissue in the cystic duct: complicating factor or coexisting pathology

The case of a 75-year-old female suffering from recurrent abdominal pain and nausea is presented. Ultrasound showed gallstones without inflammation of the gallbladder. The patient underwent laparoscopic cholecystectomy and her symptoms resolved. Histological examination of the operation specimen disclosed heterotopic pancreatic tissue within the cystic duct. An accurate clinical diagnosis of pancreatic heterotopia is difficult. The deep submucosal or intramural location of the lesion may hamper retrieval of representative biopsy material. Indications for surgery or endoscopic resection include symptomatic lesions as well as cases of unclear histological examination in order to distinguish pancreatic heterotopia from other tumors.