case_images: PMC9827538_01
case_images: The salvage EFTR with imatinib was used to treat a giant rectal GIST in this case. (A)
  and (B) Colonoscopy and endoscopic ultrasound (EUS) showed a giant sub-epithelial
  lesion originating from the muscularis propria; (C) the view of the mucosal
  incision-assisted biopsy (MIAB); (D) representative picture of hematoxylin and
  eosin staining (HE staining) for MIAB and pathology-confirmed GIST;
  (E) and (F) EUS and colonoscopy after 10-month routine imatinib therapy;
  (G)-(I) the representative views of a post-resection defect of EFTR by endoscopy; (J)
  the appearance of endoscopic suturing of the defect; (K) resected rectal
  giant GIST specimen en bloc; (L) representative endoscopic picture of the EFTR scar at
  the 3-month re-examination.
case_images: goac078f1.jpg
case_images: PMC9827538_01_goac078f1.jpg
case_images: goac078-F1
case_images: A colonoscopy revealed a giant sub-epithelial lesion with part ulceration at 2 cm proximal to the anus, involving the rectum of ~10 cm (Figure 1A). By EUS, the maximal cross-sectional dimension of it was 7.28 x 5.71 cm (Figure 1B). Mucosal incision-assisted biopsy (MIAB) was used for tissue diagnosis (Figure 1C). The pathology of MIAB confirmed GIST and immunohistology showed that the tumor was a Ki-67 4%, CD34+, CD117+, and DOG-1+ (Figure 1D). Until the operation, the tumor was 5.16 x 4.32 cm in the maximal cross-sectional dimension, almost 50% of the pretreatment volume (Figure 1E). The margin between the tumor and the adjacent normal rectal mucosa was apparent (Figure 1F). The endoscopist observed that the blood supply of the GIST was reduced (Figure 1G and H). Eventually, en-bloc tumor resection was achieved successfully without any complications (Figure 1I-K). The wound of the EFTR recovered well 3 months post-operation under colonoscopy (Figure 1L).