Pre-surgical diagnosis of neuroendocrine carcinoma of the extrahepatic bile duct: a case study

Abstract

A 70-year-old woman presented to our hospital with jaundice. Abdominal ultrasonography showed biliary duct dilatation. Blood tests revealed elevated total bilirubin and hepatobiliary enzyme levels. A contrast-enhanced computed tomography of the abdomen showed bile duct thickening with wall enhancement. Transpapillary bile duct biopsy showed an invasive carcinoma proliferating in a follicular pattern. Pathology revealed positive synaptophysin and chromogranin A and a Ki67 index >40%, consistent with a diagnosis of neuroendocrine carcinoma (NEC). After confirming the absence of distant metastases, a subtotal stomach-preserving pancreaticoduodenectomy was performed. The result of the postoperative pathology was the same as the preoperative biopsy. According to previous reports, 7 out of 28 cases with NEC/mixed adenoneuroendocrine carcinoma could be diagnosed as NEC before surgery. However, biliary cytology and bile duct scraping cytology were used in many cases;only 11 cases underwent bile duct biopsy. For the latter, 5 out of 11 cases could be diagnosed preoperatively. NEC of the extrahepatic duct often exhibits a submucosal tumor-like morphology, which may result in a false negative result with biliary cytology or bile duct scraping cytology. In our case, the transpapillary bile duct biopsy sample was sufficient to diagnose NEC. This method could be an attractive option for the diagnosis of these tumors.