Figure 2.

Endoscopic ultrasound before and after the biopsy and histology. A: An EUS before biopsy revealed a heterogeneous tumor with a cystic area and calcification spot (yellow arrow); B: An endoscopic ultrasound (EUS) from inside the submucosal tumor (SMT) filled with distilled water and an inserted EUS probe showed 5 specific layers (red circle); C: An HE stain (× 20) also showed the 5 structural layers. The hyperechoic portion showed proliferation of pseudo-pylorus glands and cystic gland dilatation without cytological atypia (blue circle); D: The 5 layers consisted of a normal mucosal layer (yellow arrow), immature fibroblasts (black arrow), pyloric glands (yellow arrow), muscularis mucosa (black arrow) and another normal mucosal layer (yellow arrow) (HE stain × 100).