Small-cell Neuroendocrine Carcinoma of the Extrahepatic Bile Duct: A Rare Case Report

Abstract

Neuroendocrine carcinoma (NEC) arising from the extrahepatic bile duct is extremely rare and commonly mistaken for cholangiocarcinoma. Therefore, NEC of the bile duct is difficult to diagnose preoperatively. Previously reported cases were resected with a diagnosis of cholangiocarcinoma and diagnosed with NEC after surgery. This paper reports an 84-year-old female with small-cell NEC of the extrahepatic bile duct, confirmed by a biopsy from an ERCP, with a review of the relevant literature. Contrast-enhanced abdomen computed tomography and magnetic resonance cholangiopancreatography revealed an approximately 1.7 cm enhancing intraductal mass in the proximal common bile duct with dilatation of the upstream bile duct. ERCP showed a long strictured segment in the proximal common bile duct with bile duct dilatation. A biopsy was performed at the site of the stricture. Histological examinations and hematoxylin-eosin staining showed the solid proliferation of small tumor cells with irregularly shaped hyperchromatic nuclei. Immunohistochemical examinations showed that the tumor cells were positive for CD56 and synaptophysin. Small-cell NEC of the extrahepatic bile duct was confirmed based on the histology and immunohistochemistry findings. The patient and their family denied treatment because of the patient's old age.

Neuroendocrine carcinoma of the common hepatic duct coexisting with distal cholangiocarcinoma: A case report and review of literature

“…A literature search in the PubMed and Web of Science databases was conducted, and articles on NEC of the intrahepatic bile duct, gallbladder, and ampulla of Vater and articles with incomplete data were excluded. A total of 48 English articles on EBNEC were obtained (Table 1 )[ 1 , 7 - 52 ]. The main clinical and pathological features of MiNEN and pure NEC were briefly summarized and compared (Table 2 ) , and the baseline characteristics of the two groups, including age, sex, tumour location, tumour size, and Ki-67, were not significantly different.…”