The natural history of upper gastrointestinal subepithelial tumors: a multicenter endoscopic ultrasound survey.

Goals: To evaluate the natural course of <3-cm upper gastrointestinal subepithelial tumors by endoscopic ultrasound (EUS) and to determine the appropriate timing for EUS follow-up.

Background: Subepithelial tumors (SETs) can range from benign lesions to tumors with malignant behavior or potential to become malignant such as gastrointestinal stromal tumors (GISTs). EUS is considered a valuable tool for their evaluation as it estimates the exact size and layer of origin, and also additional morphologic features that can suggest the diagnosis. For high surgical risk patients and when no worrisome EUS features are seen, EUS surveillance of subepithelial tumors is often used.

Methods: Fifty-one patients (mean age, 61.2+/-11.8 y; median, 63 y) with asymptomatic <3-cm SETs of second and fourth echolayer were followed for a mean period of 29.7 months (range, 3 to 84; median, 23 mo) in 3 tertiary care institutions. Evaluation included location, echolayer, tumor diameter, internal echo pattern, and outer margin of lesions by EUS. EUS was performed by using miniprobes, radial and linear echoendoscopes.

Results: Follow-up revealed increase in size and/or change in echogenic features in 7/51 (13.7%) patients. Surgical follow-up was available for 3 of 7 of these patients. Two of the fourth layer SETs, which had both increase in size and change in echogenicity were found to be GISTs (+c-kit).

Conclusions: The majority of <3-cm SETs does not change during a median of 23 months. The change in echogenicity and increase in size may indicate a GIST.