Multiple gastrinoma successfully resected with the aid of intraoperative arterial secretin injection test

Since gastrinoma is likely to develop in multiple sites, we should pay special attention to the removal of all daughter tumors, as well as the main tumor, during surgery for this disease. In a 24-year-old woman with pituitary prolactinoma, multiple gastrinomas were detected in a limited area of the pancreaticoduodenal region by preoperative imaging techniques, selective arterial secretin injection (SASI) test, and intraoperative inspection using ultrasonography. A pancreatoduodenectomy was performed, and it was intraoperatively confirmed that the serum gastrin concentration in the portal vein had decreased from 753 to 83 pg/ml (normal,<120pg/ml). However, intraoperative SASI test for the remnant pancreas showed a positive response, which prompted us to perform a histological examination of frozen sections obtained from the body and tail of the pancreas, despite the normal appearance. Many islet cell microtumors were discovered, and the remnant pancreas was completely removed. Postoperativelly, all of the tumors were immunohistochemically proven to be microgastrinomas. The patient is still disease-free, 2 years after the surgery, with a serum gastrin level of less than 30pg/ml. This report stresses the role of the intraoperative SASI test in preventing residual microgastrinomas before closure of the abdomen.