Internal hypoechoic feature by EUS as a possible predictive marker for the enlargement potential of gastric GI stromal tumors

BackgroundThere is no clinical predictor for the enlargement potential of gastric GI stromal tumors (GISTs) during the follow-up observation period.ObjectiveThe aim of our study was to identify predictive markers for the enlargement potential of gastric GISTs on the basis of various endosonographic features determined at the initial examination.DesignSingle-center retrospective analysis.SettingAcademic university hospital in Japan.PatientsAll patients (n = 74) with histologically diagnosed GISTs in the stomach underwent EUS.InterventionEUS.Main Outcome MeasurementsWe analyzed the following endoscopic and EUS features: mucosal ulceration, irregular shape, irregular border, heterogeneity, internal hyperechoic spot, hypoechoic area, and anechoic area of gastric GISTs in 3 groups according to tumor size. Furthermore, we compared the characteristics between increased growth and unchanged growth of GISTs, that were defined on the basis of the novel tumor growth index: changes in tumor volume/follow-up interval (days between initial EUS and second EUS) (mm3/day).ResultsThe presence of heterogeneity (P = .016) and anechoic area (P = .003) was significantly highest in the group with the largest tumor size. The increased growth group had a higher presence of hypoechoic area than did the unchanged growth group (84.2% vs 51.9%, P = .023). Multivariate analysis showed that the presence of a hypoechoic area was an enlargement-associated factor (odds ratio 5.38; 95% confidence interval 1.19-24.39; P = .029).LimitationsRetrospective design of the study.ConclusionsThe internal hypoechoic area determined by EUS may be a predictor for the enlargement potential of gastric GISTs.