[Endoscopic ultrasonography of malignant tumors in the upper abdomen].

Endoscopic ultrasonography (EUS) of the upper gastrointestinal tract is a newly developed, non-invasive investigational method. It combines the direct optical picture of the endoscope with a simultaneous ultrasonographic image of the whole wall of the oesophagus, stomach and duodenum as well as organs and other structures with anatomical relations to the upper gastrointestinal tract. EUS is evaluated for its capacity with respect to cancer of the oesophagus, stomach, pancreas, biliary tree and neuroendocrine tumours, the emphasis being laid on TNM-classification, assessment of resectability and comparison with other imaging techniques. It is concluded that EUS is well-suited for assessing tumour infiltration and thereby also the resectability of these cancer types. Judging whether lymph nodes visualized by EUS are malignant or not is difficult when operating solely from endosonographic and quantitative criteria, and while the sensitivity of EUS for detecting lymph node metastases is in most situations superior to other investigational methods, the specificity and ability to visualize distant metastases is poor. For these purposes the optimal solution appears to be a combination of EUS with CT and/or ultrasound scanning. Future possibility of EUS-guided biopsy will strengthen the method's position in the diagnostic armoury concerning malignant disease in the upper gastrointestinal tract.