[Pancreatic cystic lesions of difficult diagnosis]

Cystic lesions of the pancreas include pseudocysts (90%), cystic tumors and true cysts. Preoperative diagnosis will guide the therapeutic strategy. Certain malignant or potentially malignant cysts (mucinous cystadenomas and cystadenocarcinomas) should be removed surgically while others (pseudocysts and serous cystadenomas) are almost always benign. In 3 out of 4 cases, the clinical setting guides diagnosis and with adequate imaging (sonography, computed tomography, endosonography) the correct diagnosis can be obtained. Inversely, the nature of a unique macrocyst it is often difficult to identify. Puncture is useful to determine tumor markers which are sometimes helpful in complementing information provided by imaging techniques.