title: Two Cases of Rectal Neuroendocrine Tumor Resection Combined with Dissection of the Circular Muscle Layer Using the Endoscopic Submucosal Dissection Technique.
abstract: Generally, lesions of rectal neuroendocrine tumors (NETs) 10 mm or smaller are less malignant and are indicated for endoscopic therapy. However, the vertical margin may remain positive after conventional endoscopic mucosal resection (EMR) because NETs develop in a way similar to submucosal tumors (SMTs). The usefulness of EMR with a ligation device, which is modified EMR, and endoscopic submucosal dissection (ESD) was reported, but no standard treatment has been established. We encountered 2 patients in whom rectal NETs were completely resected by combined dissection and resection of the circular muscle layer using the ESD technique. Case 1 was an 8-mm NET of the lower rectum. Case 2 was NET of the lower rectum treated with additional resection for a positive vertical margin after EMR. In both cases, the circular muscle layer was dissected applying the conventional ESD technique, followed by en bloc resection while conserving the longitudinal muscle layer. No problems occurred in the postoperative course in either case. Rectal NETs are observed in the lower rectum in many cases, and it is less likely that intestinal perforation by endoscopic therapy causes peritonitis. The method employed in these cases, namely combined dissection and resection of the circular muscle layer using the ESD technique, can be performed relatively safely, and it is possible to ensure negativity of the vertical margin. In addition, it may also be useful for additional treatment of cases with a positive vertical margin after EMR.
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Kumpei
authors.initials: K
authors.lastname: Honjo
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Kure
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ichikawa
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ro
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Takahashi
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Niwa
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Ishiyama
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Kiichi
authors.initials: K
authors.lastname: Sugimoto
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kojima
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Michitoshi
authors.initials: M
authors.lastname: Goto
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tomiki
authors.affiliation: Department of Coloproctological Surgery, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Department of Human Pathology, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fukumura
authors.affiliation: Department of Human Pathology, Juntendo University Faculty of Medicine, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yao
keywords: Endoscopic mucosal resection with a ligation device; Endoscopic submucosal dissection; Neuroendocrine tumor