Intraoperative Sonographic Localization of Insulinoma: Case Reports and Review of Literature

Insulinomas, a rare clinical entity, are usually small, single, benign and intrapancreatic in location. Several modalities are available for preoperative localization of insulinomas. Intraoperative ultrasound is an important tool used for localization as well as to find anatomical relation of tumor to surrounding tissue. We are reporting three cases of insulinomas with brief discussion on modalities used for localization. After biochemical confirmation of hyperinsulinemia, preoperative localization was done initially by computed tomography followed by intraoperative ultrasonography. Preoperative localization by computed tomography was successful in all the cases but missed an additional lesion in one of the patients which was picked up by intraoperative ultrasonography (IOUS) that changed surgical management. Preoperative localization may not be successful in all the cases. Intraoperative direct inspection, palpation and ultrasound can be used to identify lesions in the cases where preoperative localization was unsuccessful.