Economical preoperative diagnosis of pancreatic insulinomas

An insulinoma is the most common pancreatic endocrine tumor. Typical is the presence of a solitary tumor. In 10 % of the cases an insulinoma may occur in multiple sites, especially in MEN syndrome. Malignant insulinomas appea r in 10% of cases. Insulinomas occur at every age, but mainly about the 50t h year. Because of its small size (a diameter of 1-2 cm) diagnostic localiz ation is often difficult. With costly imaging techniques such as CT and MRI , only 60 % of the adenomas can be detected preoperatively, If reoperation is a possibility, CT and MRI are advisable. Based on our own experience and the reports of other authors, we advise the combination of transabdomial u ltrasound and endosonography for the primary operation. With these methods 90 % of the adenomas can be localized preoperatively. If the clinical and b iochemical insulinoma diagnosis is definite, explorative laparotomy is indi cated, even without preoperative morphological tumor detection. With intrao perative ultrasound and systematic palpation more than 97 % of insulinomas can be found and resected. We report the case of a 54-year-old woman with u nsuccessful preoperative localization in spite of extensive clinical, bioch emical and imaging procedures over a 6-month period.