[Identification of insulinomas by endoscopic ultrasonography]

The aim of this study is to compare EUS and the others diagnostics tests in the correct localization of insulinomas.

We prospectively investigated 30 patients with endoscopic ultrasound with a clinical diagnosis of insulinomas prior to surgical exploration. They were submitted to abdominal ultrasonography, spiral computed tomography and four patients were submitted to magnetic ressonance before EUS. Surgery was the gold standard for tumor localization.

Twenty-six tumors were benign (86.6%) and four were malign (13.4%). The median size tumors detected by EUS was 1.5 cm. The overall sensitivity of EUS in identifying insulinomas was 86.6% compared to 33% for CT, 40% to MRI and 90.9% to IUS. In 12 patients we were able to perform EUS-guided fine needle aspiration. Insulinoma was diagnosed in ten cytological specimens (83.3%). Tumors located in the head and body of the pancreas were seen by EUS in all patients, respectively but those located in the tail were diagnosed only in 55.5% of the cases.

EUS has a high sensibility in the identification and localization of pancreatic insulinomas and should replace traditional methods of image when clinical suspicion is high.