Fig. 2

CT findings of portal annular pancreas and operative procedures. a Coronal image. The portal vein is completely encircled by the aberrant parenchyma of the portal annular pancreas (black asterisk). b, c Horizontal images. The aberrant parenchyma (black asterisk) is cranial to the confluence of the portal vein and the splenic vein. c The confluence of the portal vein and splenic vein, and b 5-mm cranial to c. Of note, the main pancreatic duct (white arrowhead) in a to c runs ventral to the portal vein toward the duodenum. d Preoperative simulation. Three pancreatic transections including additional resection of the aberrant parenchyma (black asterisk) are needed to remove the tumor and create the single cut margin containing the main pancreatic duct in the distal pancreas. e Actual operative procedure performed. The tumor is removed by two pancreatic transections preserving the aberrant parenchyma (black asterisk). The dotted line indicates the main pancreatic duct (d, e). PV: portal vein, SPV: splenic vein, T: tumor