Diagnosis and surgical treatment of insulinoma: report of 40 cases

Background and objective: Most insulinomas are solitary, benign and functional neuroendocrine pancreatic tumors which give rise to manifold symptoms. Their preoperative localization is often unclear, but the cure rate after their excision is very high. It was the aim of this study to analyse and evaluate our group of patients with regard to preoperative tumor localization and overall surgical results. Methods: Data were collected as part of prospective observations and retrospective evaluation of all patients treated for insulinoma between 1987 and 2003 at the department of visceral-thoracic- and vascular surgery at the Philipps University of Marburg. In all of them the diagnosis had been confirmed by a fasting test. Results: 40 patients with an insulinoma (22 females, 18 males; average age 52 years [range 12-87 years]) had been operated. The sensitivity of preoperative localization was 65% for endoscopic ultrasound, 33% for ultrasound, 33% for Computed tomography, 15% for magnetic resonance imaging and 0% for somato-statin-receptor scintigraphy. But all insulinomas were identified intraoperatively by pancreas dissection and ultrasound (IOUS). 38 patients were completely cured by excision of the tumor. Conclusion: After positive biochemical and fasting tests and exclusion of diffuse abdominal metastases by transabdominal ultrasound, all patients should without further preoperative investigations undergo surgical excision of the insulinoma after bidigital palpation of the pancreas and IOUS. But if laparoscopic excision is planned, endoscopic ultrasound should be undertaken preoperatively.