[Accuracy of endoscopic ultrasonographic impression compared with pathologic diagnosis in gastrointestinal submucosal tumors].

Background/aims: Endoscopic ultrasonography (EUS) is a valuable imaging modality for the evaluation of gastrointestinal submucosal tumor (SMT). EUS is helpful in assessing the layer of origin, tumor diameter, shape, border characteristics, and internal echo patterns of SMTs and thus makes it possible to predict histologic diagnosis with educated guess. However, some studies have found no significant differences in EUS features between benign and malignant mesenchymal tumors. By comparing EUS impressions with histologic diagnosis, we evaluated the accuracy of EUS in differential diagnosis of gastrointestinal SMTs.

Methods: 58 cases of gastrointestinal SMTs with both EUS findings and pathologic reports were compared retrospectively from August 2001 to September 2003.

Results: 34 patients had lesions in the stomach and 13, 8, 3 in the esophagus, duodenum, and colon respectively. Benign lesions were predominant (46 of 58). The EUS and pathologic diagnosis coincided in 46/58 (79.3%) of the cases. Use of EUS led to the correct diagnosis in 7/9 (77.8%) of malignant GISTs (gastrointestinal stromal tumor) and leiomyosarcomas. Two small malignant gastric GISTs were diagnosed as benign with EUS.

Conclusions: EUS is a useful tool in the differential diagnosis of gastrointestinal SMTs and predicting malignant lesions. However, some malignant GISTs were diagnosed as benign tumor with EUS examination.