Operative ultrasonic features of insulinomas

The technique of operative pancreaticosonography is described as a method of localizing occult insulinomas. The specific ultrasonic features of two small but palpable insulinomas are compared with those of other small lesions in the pancreas. Insulinomas are ultrasonically hypoechoeic and well-defined, with smooth borders, they deform but do not infiltrate surrounding structures, and they cause some dilatation of the secondary pancreatic ducts. Real-time, high resolution, intraoperative ultrasonic pancreatography is suggested as an adjunct to assist in the localization of insulinomas at surgery.