[Contribution of echography to the diagnosis of cancer of the exocrine pancreas. Pitfalls and limits. Results of guided biopsy].

The importance of ultrasound in the diagnosis of primary pancreatic adenocarcinoma is due to the wide use of ultrasound as a first diagnostic modality in the case of abdominal problems, immediately after the physical examination. The results of the ultrasound examination allow the physician to choose the best way to explore the pancreas further (CT, pancreatography, angiography, MRI). The technical quality of the ultrasound examination is mandatory and the radiologist must be able to recognize its insufficiencies. The pancreatic adenocarcinoma is difficult to see with ultrasound: infiltration, ill-defined borders and echopattern; the lymph node or metastatic involvement is frequent and remains a good diagnostic sign. Many pitfalls can be attributed to this technique; the variations of the normal anatomy, the diversity and variable appearance of pancreatic lesions and the association with pancreatitis. The US-guided puncture represents a way to limit the use of diagnostic exploratory laparotomy.