Fig. 1. A representative case of three-dimensional (3D) reconstruction of gastric subepithelial tumor (case 5). (A) A cushion-sign-negative 2-cm subepithelial tumor on the posterior wall below the gastric cardia. (B) The tumor was observed as a hypoechoic mass with a clear border arising from the fourth layer on endoscopic ultrasound, which suggests a mesenchymal tumor. A mucosal incision biopsy was performed, and the pathology results revealed leiomyoma. (C) The tumor was identified on thin-slice computed tomography images acquired in three directions. (D) A reconstructed 3D image. (E) The 3D image was freely rotatable.

Fig. 2. Differentiation using the morphology of gastric subepithelial tumors. (A) Scatter diagram showing the correlation between circularity and sphericity. A linear correlation is observed but without statistical significance (r=0.461, p=0.084). (B) Sphericity of the 15 lesions. (C) The sphericity of leiomyomas also tends to be lower than that of other mesenchymal tumors. GIST, gastrointestinal stromal tumor.

Graphical abstract