Pancreatic insulinomas: diagnosis and surgical treatment of 74 patients

To summarize retrospectively the experience in diagnosis and surgical treatment of pancreatic insulinoma.

74 patients who had been operated on and confirmed pathologically from July 1967 to July 2001 were enrolled. They were 37 men and 37 women, aged 41.91 years on average.

In all patients with typical Whipple's triad, the ratio of insulin to glucose was measured over 0.3 for at least one time. 52.70% of the patients were once misdiagnosed, and only 20.27% of them were correctly diagnosed in a year after onset of symptoms. Their average course of the disease was 3.36 years. B-ultrasonography and endoscopic ultrasonography (EUS) showed a low positive rate for localization of insulinoma. CT and magnetic resonance imaging (MRI) could correctly detected 63.41% and 63.64% of tumors respectively, in sharp contrast to a localization rate of 90% for arterial stimulation and venous sampling (ASVS). Single insulinoma was observed in 66 patients (89.19%), multiple insulinoma in 2 (2.70%), hyperplasia in 4 (5.41%), and malignant insulinoma in 2 (2.70%). Most (85.29%) of the benign insulinomas were less than 2 cm in diameter. Simple enucleation was the major operative procedure for benign tumors. In 88.52% of the patients, glycemia increased to normal in 30 minutes after tumor excision, and in the remaining patients within 2 hours. 97.26% of the patients experienced temporary hyperglycemia but recovered in a week. The major complications of insulinoma included pancreatic fistulae (27.27%) and pancreatitis (5.19%).

Better recognization of insulinoma and its rational examination are essential to early diagnosis. CT can be first used for localization, otherwise ASVS is used. Surgery is the major choice for the treatment of insulinoma, but cautions should be taken to pancreatic fistulae after operation.