Gastrointestinal stromal tumors (GIST): Sonographic and endosonographic findings

Between 1993 and 1999 we found 32 GIST in the upper GI-tract. 6 of them were localized in the esophagus, all of them benign. Endoscopic ultrasound (EUS) is the diagnostic tool of choice to classify an esophageal impression. Typical GIST appears as a sharply defined tumor from the fourth layer (muscularis), sometimes with calcifications. In stomach 18 stromal tumors were found (range 10-70 mm), six of them causing an acute upper gastrointestinal bleeding, two an anemia. Endoscopic suspicion can be confirmed by EUS; in 13 of 18 cases we could detect the tumor also by percutaneous sonography. The typical sonographic image of benign GIST is a homogeneous tumor deriving from the fourth layer of gastric wall. In 12 of the gastric tumors operation was performed, 7 times proving malign GIST. All of the malign GIST measured 30 mm or more. An inhomogeneous texture of tumor is a suspicious for malignancy. Another 5 tumors derived from duodenum or small bowel, all af them advanced tumors between 60 and 100 mm. The two duodenal GIST were detected by endoscopy (GI-bleeding/anemia); the three small bowel tumors by transcutaneous sonography, but allocating to small bowel was difficult.