Curative resection of a huge malignant pancreatic endocrine tumor by pancreatoduodenectomy with portal and superior mesenteric vein resection and reconstruction using the right ovarian vein: report of a case.

Nonfunctioning pancreatic endocrine tumors (PETs) are rare and generally asymptomatic. A 68-year-old woman who had refused treatment for a pancreatic mass, revealed by ultrasonography to be 55 mm in diameter, was referred to us again 29 months later with jaundice. Investigations showed an 82-mm tumor in the head of pancreas, exposed from the papilla of Vater to the duodenal lumen. After biliary decompression and drainage, we performed pancreatoduodenectomy with resection of the portal vein and superior mesenteric vein, followed by reconstruction using a cylindrically customized autologous graft harvested from the right ovarian vein. The tumor was resected curatively. Microscopically, it consisted of trabecular and ribbon-like arrangement of neoplastic cells. Immunohistochemical staining was positive for chromogranin A and synaptophysin and negative for insulin, gastrin, glucagons, somatostatin, and pancreatic peptide. Although metastasis was detected in a lymph node along the superior mesenteric vein with perineural invasion, the portal and superior mesenteric veins had not been invaded. The diagnosis was well-differentiated nonfunctioning PET. The patient had an uneventful postoperative course, and there has been no evidence of recurrence in 12 months.