Oval mucosal opening bloc biopsy after incision and widening by ring thread traction for submucosal tumor

Figure 6 Direct view of capsule and abundant vessels of gastrointestinal stromal tumors. With more insufflation, both ring threads expanded the oval incision to a round shaped incision (green arrows) from which the tumor capsule was clearly recognized. An approximately 7-mm cut of the tumor capsule (yellow arrows) by Dual knife made it possible to confirm the tumor (blue arrows) with abundant tumor vessels.