Pancreatic insulinoma: current issues and trends

Although insulinomas are very rare tumors, they are the most common pancreatic neuroendocrine neoplasms. The incidence in general population is 1-4 per 1,000,000 yearly but the incidence is higher in autopsy studies. The malignancy of insulinomas is difficult to be predicted on the basis of their histological features, and the current WHO classification has been re-evaluated. This review aimed to summarize classical knowledge with current trends in the diagnosis and treatment of insulinomas.

A Medline search using terms "insulinoma", "treatment" and "neuroendocrine tumors" was conducted. Additional references were sourced from key articles.

Surgery is the treatment of choice for insulinoma and has an extremely high success rate. Medical treatment is also available but only for patients who are unable or unwilling to undergo surgical treatment. Preoperative localization is necessary for planning the surgical approach. Many methods exist for localization of an insulinoma and can be invasive and non-invasive. The combination of biphasic thin section helical CT and endoscopic ultrasonography (EUS) has an almost 100% sensitivity in localizing insulinomas. Laparoscopic ultrasound is mandatory to localize intraoperatively these tumors. EUS-guided fine needle tattooing is an alternative method of localization in case of lack of laparoscopic ultrasound.

Laparoscopic resection for benign insulinomas is the procedure of choice, whereas pancreatectomy is reserved for large, potentially malignant tumors.