Neuroendocrine tumor of the extrahepatic bile duct: A case report

Abstract

Introduction: Neuroendocrine tumors (NETs) of the extrahepatic bile ducts are extremely rare neoplasms arising from endocrine cells and have variable malignant potential. They most commonly occur in young females and usually present with painless jaundice.

Presentation of case: Here we present the case of an asymptomatic 57-year-old woman with NET of the common bile duct that was incidentally discovered on abdominal ultrasound during a medical examination. She was admitted to our hospital with a diagnosis of hepatic hilar tumor. Computed tomography revealed the tumor surrounding the hepatic hilum and duodenum. Magnetic resonance cholangiopancreatography revealed a filling defect of the common bile duct with morphology suggestive of external compression. Endoscopic ultrasound confirmed a submucosal tumor of the duodenal bulb measuring 30×20mm in size. The patient qualified for surgery with a preoperative diagnosis of submucosal tumor of the duodenal bulb. Intraoperative examination revealed that the tumor location involved the common bile duct and/or cystic duct with no signs of invasion to other organs or metastatic lymph nodes. Excision of the biliary ducts and tumor was followed by Roux-en-Y anastomosis. Histological results showed NET grade 1.

Discussion: Preoperative diagnosis of NETs is difficult because of their rarity. A definitive diagnosis is usually established intraoperatively or after histopathological evaluation.

Conclusion: For these tumors, surgical resection is currently the only treatment modality for achieving a potentially curative effect and prolonged disease-free survival.

Keywords: Case report; Extrahepatic bile duct; Neuroendocrine tumours; Surgical treatment; Unusual biliary tumours.

Fig. 1

Computed tomography revealed a tumor, with a 3-cm diameter, surrounding the hepatic hilum with the compression of the common bile duct from the outside. The tumor was enhanced in the early phase (single arrow). The extrahepatic bile duct was visible (double arrows).

Fig. 2

Magnetic resonance cholangiopancreatography showed a filling defect of the common bile duct with no dilatation of the intrahepatic bile duct.

Fig. 3

Endoscopic ultrasound showed a 30 × 20-mm submucosal tumor of the duodenal bulb.

Fig. 4

Histological examination revealed that the tumor, generated from the intramuscular layer of the common bile duct and located within the muscle layers, compressed the lumen of the bile duct.

Fig. 5

Immunohistochemical analysis showed that neoplastic cells were positive for chromogranin A, synaptophysin, and CD56. The proliferative index (Mib-1) was <2%.