RESUMEN
Insulinoma in most cases is monohormonal orthoendocrine tumor. This fact limits its searching area by a pancreas. However the insulinoma's clinical picture can be caused by other pathology. Therefore the main task of visual the tumor but also to use all the possibilities of each method for defining type of surgery and avoiding such errors and complications, as pancreatorrhage, damage of bile or pancreatic duct, necrosis of duodenal wall, etc. On the basis of our own experience of endoscopic ultrasound for 61 patients with 66 insulinomas, we have allocated the basic variants of insulinoma ultrasound pictures: hypoechoic, heteroechoic, isoechoic tumor, and also foci without a trustworthy contour. On the basis of the analysis of our own errors we have essentially added the technique, having used multiplane pancreas scanning and biplane tumor scanning. Important points in EUS algorithm are also the following items: detecting tumor relationship to pancreatic surface, distance from the tumor to the ducts, gastrointestinal wall and vessels--for definition of possibility of the tumor enucleation; careful scanning of pancreas even after detecting one tumor--for an exception of multiple tumors, especially at MEN-I; careful scanning of a contour of the gland for an exception of parapancreatic insulinomas; estimation of vascularization not only of the detected tumor and suspicious foci, but also of all the gland--for detection of hypervascularized isoechoic tumors; revealing and the description of focal changes, especially more homoechogeneous in comparison with surrounding parenchyma-- for selection patients for examination by other methods; scanning of zones of possible metastasis. Examination of patients with organic hyperinsulinism demands combined application of two or more techniques. Use of all modern possibilities of endosonography can put this technique on one of the first places in the diagnosis of insulinomas.