Endosonography in diagnosis of insulinoma

AIM: In a prospective study endoscopic ultrasonic localisation of clinically suspected insulinomas was compared with the findings of abdominal ultrasound, computed tomography and magnetic resonance imaging. METHOD: From Dec. 1990 to Jan. 1995 11 patients (8f, 3m, median age 42 [27-79] years) were enrolled in the study. The preoperative endosonographic findings were compared to surgery (n = 7) or clinical follow-up (n = 4). RESULTS: Endoscopic ultrasound identified a solitary tumour (mean size 12.4 mm) in 7 of 11 patients, which was proven at surgery in 5 patients and by transhepatic portal venous sampling after negative partial pancreas resection in 1 patient. One patient is still awaiting surgery. Clinical follow-up (n = 2) and negative intraoperative and histological findings of partial pancreas resection (n = 1) confirmed a true negative examination in 3 patients. One patient with negative endoscopic ultrasound is still under medication for recurrent hypoglyctemia. Abdominal ultrasound (n = 11), computed tomography (n = 11) and magnetic resonance imaging (n = 5) were negative in all investigated patients. CONCLUSION: Endoscopic ultrasound is highly accurate for localisation of insulinomas and should be performed early in the preoperative management of these patients.