RESUMO
BACKGROUND/AIMS: A gastrointestinal mesenchymal tumor contains a leiomyoma and gastrointestinal stromal tumor (GIST). The natural course can vary according to the histology and other characteristics. This study evaluated the natural course of a benign mesenchymal tumor in the upper gastrointestinal tract using endoscopic ultrasonography (EUS). METHODS: Submucosal mesenchymal tumors are considered benign according to the following criteria of EUS: 1) the tumor originates from the muscularis mucosa or muscularis propria; 2) is well demarcated, homogenous and hypoechoic; and 3) has a regular surface. In this study, the changes of size, internal echo pattern and marginal regularity were evaluated retrospectively in 26 lesions that all were < 3 cm and were followed up for more than 2 years. RESULTS: The average size of the tumors on EUS was 11.5 mm. The mean follow-up period was 47.4 months. The follow-up EUS revealed no change in echo features in any patient. In only one patient, the size of the tumor increased from 26 to 34 mm without a change in the internal echo or marginal regularity after 24 months. This patient underwent a laparoscopic gastric wedge resection. The pathologic diagnosis was a leiomyoma. CONCLUSIONS: Most small submucosal tumors that are compatible with the EUS criteria of a benign GIST/ leiomyoma do not change over a period of 24 months, and the EUS criteria are effective in diagnosing benign GISTs/leiomyomas. A benign GIST/leiomyoma at EUS might be followed up by EUS at an interval of 2 years.