Objective:To study the methods used for diagnosis and surgical treatment of insulinoma.
Methods:We retrospectively analyzed 55 cases of insulinoma treated in our hospital from 1988 to 2009.
Results:Of the 55 cases, 7 of non-functional insulinoma, 48(87.27%) had typical Whipple′s triad and the IRI/G was greater than 0.3, and were diagnosed as functional insulinoma. The diagnostic sensitivity of transabdominal ultrasonography was 83.64%(46/55),  CT was 62.07%(18/29),  MIR was 40.00%(4/10), endoscopic ultrasonography was 100%(8/8), intraoperative ultrasonography was 90.00%(9/10) and DSA was 40%(2/5). Simple enucleation was performed in 48 patient-times, resection of pancreatic body and tail(or just tail) in 5 cases, resection of pancreatic body and tail plus the spleen in 3 cases, central resection of pancreas in 1 case and pancreaticoduodenectomy in 1 case. The diameter of 95.00% (57) of tumors was ≤2 cm, and  23.33% (14) tumors were located in the head of the pancreas, 33.33% (20) in the body, and 43.33% (26) in the tail. Three patients had multiple tumors.  All of the 55 cases were diagnosed as insulinoma pathologically. None was malignant. After operation, blood glucose became normal in all cases but pancreatic fistula occurred in 1 case.
Conclusions:Whipple′s triad and IRI/G>0.3 is the main basis for the qualitative diagnosis of insulinmoma. Combined methods including Ultrasonography, CT, MIR, and endoscopic ultrasonography should be used for localization diagnosis before operation. The positive localization rate of endoscopic ultrasonography is the highest. The application of intraoperative palpation and intraoperative ultrasonography shows great significance for insulinoma localization. Simple enucleation is the most common and optimal surgical method.