Extensively Invasive Gallbladder Cancer from Intracholecystic Papillary Neoplasm Treated with Pylorus-Preserving Pancreaticoduodenectomy and Extended Cholecystectomy: A Case Report and Literature Review.

Accurate preoperative diagnosis of ICPN, including the extent of tumor invasion is challenging. To ensure complete curability, the development of an optimal surgical strategy considering preoperative examinations and intraoperative findings is essential.