Large-cell neuroendocrine carcinoma of the common bile duct: a case report and a review of literature

BACKGROUND: Large-cell neuroendocrine carcinoma (LCNEC) of the bile duct is extremely rare and is a high-grade type of neuroendocrine tumor with an aggressive clinical course. Here, we report a case of LCNEC of the extrahepatic bile duct. CASE PRESENTATION: An 80-year-old man presented with severe jaundice. Endoscopic retrograde cholangiography and enhanced computed tomography revealed complete obstruction of the common bile duct (CBD) by a dense tumor measuring 1.5 cm in diameter. Although there were no malignant cells in the biliary brush cytology, we suspected a cholangiocarcinoma and performed extrahepatic bile duct resection. Histologically, the LCNEC occupied most of the places deeper than the stratum submucosum and an adenocarcinoma component, approximately 15%, was present in the mucosa. There were no transitional areas between the two components. Immunohistochemically, the LCNEC cells were reactive for CD56 and synaptophysin and had a high MIB-1 index (72%). The patient died of multiple liver, lung, and peritoneal metastases 3 months after surgery. CONCLUSIONS: LCNEC of the CBD is particularly rare and has a very poor prognosis. Only five cases have been reported in the literature; therefore, there is no established effective therapy, including surgery, for LCNEC of the CBD at present. An accumulation of additional cases and further studies of multimodal treatment are required in the future to improve the prognosis.