Clinicopathological characteristics of extrahepatic biliary neuroendocrine neoplasms in the gallbladder, extrahepatic biliary tract, and ampulla of Vater: A single-center cross-sectional study.

AoV and non-AoV tumors had significant differences in the histologic grade, Ki67, and PNI. Patients with non-AoV tumors had an increased risk for survival and recurrence than those in the AoV group. For extrahepatic biliary NENs, early detection of tumors, adequate surgery, and aggressive adjuvant treatment for high-risk patients are important to achieve long-term survival and prevent disease recurrence.