Intraoperative ultrasound of the pancreas in hyperinsulinism

: In four cases of hyperinsulinism proven clinically and by blood chemistry the value of intraoperative sonography of the pancreas is emphasized. An insulinoma could be localized preoperatively in two patients. In one of these two cases intraoperative sonography detected additional insulinomas. In the remaining two patients the negative preoperative examinations and surgical palpation was confirmed by using this method: diffuse islet cell hyperplasia was the final diagnosis in both cases.