Background: Differentiating between benign and malignant submucosal tumors is difficult. Moreover, the natural course of benign-appearing SMTs is not clearly elucidated.
Objectives: To evaluate the natural course of upper gastrointestinal SMTs by endoscopic endosonography.
Methods: We followed 25 consecutive patients with small (< 40 mm) SMTs for a mean period of 19 months. Evaluation included maximal tumor diameter, internal echo pattern, and outer margin of lesions.
Results: Follow-up revealed no change in echo features in 24 of 25 patients (96%). In only one patient a homogenous hypoechoic smooth margin lesion converted to a non-homogenous tumor with an irregular outer margin. This lesion also increased in size from 30 to 38 mm. On surgical removal this tumor was found to be a stromal tumor with high malignant potential.
Conclusions: Most small SMTs do not change during a period of 19 months and a conservative policy of surveillance is warranted.