Distal Pancreatectomy for a Solid-Pseudopapillary Neoplasm of the Pancreas with the Preoperative Suspicion of Major Arterial Involvement: A Case Report

Background: Solid-pseudopapillary neoplasms (SPNs) of the pancreas are a relatively rare type of tumor with low-grade malignant potential. Although surgical resection provides a cure in most of cases, the safety and efficacy of surgical treatment for tumors with major arterial involvement remains unknown. Case presentation: A 30-year-old man with a preoperative diagnosis of SPN was referred to our department. Abdominal computed tomography (CT) revealed a lobulated mass located at the pancreatic body, with a maximum diameter of 11 cm. The celiac artery (CA) and splenic artery (SA) were surrounded (by approximately 270° and 360°, respectively) by an expansively growing tumor, while the common hepatic artery (CHA), superior mesenteric artery (SMA) and superior mesenteric vein (SMV) were contacted by the tumor for a distance of 26.6, 42.8, and 43.5 mm, respectively on CT. The arterial walls of the CHA and SMA were smooth without any irregularity; however, narrowing and irregularity of the SA was present. The imaging findings strongly suggested an SPN of the pancreas; the involvement of the SA, CA, SV and SMV by the tumor was suspected. Distal pancreatectomy with celiac axis resection was planned. After laparotomy, the CHA, SMA, CA, and SMV were safely preserved, and the tumor was resected by distal pancreatectomy alone. A pathological examination confirmed that the tumor was an SPN with a malignant component. Although the tumor pathologically invaded the retropancreatic tissue, splenic artery and splenic vein, the resected margin was negative. Conclusion: Although the preoperative examination delineated the gross expansion of an SPN around the CA, CHA, and PV, these vessels were safely preserved during pancreatectomy. This case suggests that the surgical resection of the SPN may occasionally be attempted; even in cases with compressed and deviated by the tumor.