Successful Localization by Hyperselective Arterial Calcium Injection Test for Surgical Resection of Insulinoma: A Case Report

Surgery is the main treatment for insulinoma, and precise preoperative localization is important to determine the extent of resection and to rule out multiple lesions. The selective arterial calcium injection (SACI) test is instrumental in the localization of insulinoma. Here we report a patient in whom the exact location of pancreatic insulinoma could not be determined by the conventional SACI test, and thus surgery was replaced with oral diazoxide. The hyperselective SACI test subsequently localized the lesion accurately, allowing surgical resection of the pancreatic body and tail while preserving the pancreatic head. We recommend the use of the hyperselective SACI test when the conventional SACI test fails to accurately determine the location of insulinoma lesions within the pancreas.