Role of EUS in the preoperative localization of insulinomas compared with spiral CT

Background: Preoperative radiologic localization of insulinomas often fails because of the small size of these tumors. Endoscopic ultrasound (EUS) can localize insulinomas In up to 80% of the cases. The aim of this study was to compare EUS and computed tomography (CT) diagnostic accuracy for insulin omas, Methods: We reviewed medical records from 12 patients (10 women) with a bio chemical diagnosis of hypoglycemia and hyperinsulinism from 1 university ho spital and 1 community hospital. A diagnosis of insulinoma was ultimately m ade in all cases and before surgery the patients underwent abdominal US, sp iral CT and EUS in an attempt to precisely localize the tumor. Surgery was considered the standard for tumor localization. Results: Ten tumors were benign (83.3%) and 2 were malignant (16.7%). The o verall sensitivity of EUS in identifying insulinomas was 83.3% compared wit h 16.7% for CT. Tumors not detected by EUS had a mean size of 0.75 cm, EUS- guided fine-needle aspiration was possible in only 3 patients, with a posit ive cytologic diagnosis in 2 (66.6%). Tumors located in the head end body o f the pancreas were identified by EUS in all patients, but those located in the tail were diagnosed in only 50% of the cases. Conclusions: EUS is superior to spiral CT and should replace it for the det ection of pancreatic insulinomas, EUS identification depends on the site an d size of the tumor.