Mucosal-incision assisted biopsy for suspected gastric gastrointestinal stromal tumors

Figure 1 Case 1 of gastrointestinal stromal tumor which underwent mucosal incision assisted biopsy. A: Endoscopic image of the lesion. The lesion was covered by normal mucosa with a bridging fold; B: Endoscopic ultrasonography imaging of the lesion with a miniature probe. The lesion was located in the 4^th layer (muscularis propria); C: Two mucosal incisions were made to expose a portion of the lesion; D: Tissue samples were obtained using biopsy forceps; E: Closure of the mucosal incisions with endoclips; F: Pathological examination of the biopsied specimen. Immunohistochemical analysis showed that the lesion was positive for c-Kit and CD34 and negative for desmin. The biopsy samples also contained normal smooth muscle tissue, which was negative for c-Kit and CD34 and positive for desmin.

Figure 2 Case 25 of submucosal tumor with an extraluminal growth pattern in which mucosal incision assisted biopsy was non-diagnostic. A: No submucosal tumor (SMT)-like lesion was initially detected; B: Later during the procedure, the SMT-like lesion was detectable; C: Conventional endoscopic ultrasonography showed that the lesion was located in the 4^th layer (muscularis propria) and had an extraluminal growth pattern; D, E: Due to the risk of perforation, the lesion could not be clearly exposed. The lesion appeared to be covered with the normal smooth muscle of the muscularis propria; F: Closure of the mucosal incision with endoclips. Pathological examination of the biopsy samples suggested gastrointestinal stromal tumor, but was not conclusive.