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©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Oct 26, 2025; 13(30): 110330
Published online Oct 26, 2025. doi: 10.12998/wjcc.v13.i30.110330
Published online Oct 26, 2025. doi: 10.12998/wjcc.v13.i30.110330
Spontaneous colonic transection following pathologic complete response to pembrolizumab in high microsatellite instability colorectal cancer: A case report and review of literature
Chungyeop Lee, Min Hyun Kim, In Ja Park, Seok-Byung Lim, Yong Sik Yoon, Chan Wook Kim, Jong Lyul Lee, Eun Jung Park, Division of Colon and Rectal Surgery, Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, South Korea
Eu-Tteum Choi, Department of Nursing, Asan Medical Center, Seoul 05505, South Korea
Author contributions: Lee C and Kim MH contributed to the manuscript writing and editing and data collection; Lee C and Choi ET contributed to the data analysis; Kim MH contributed to the conceptualization and provided supervision; All authors read and approved the final manuscript.
Informed consent statement: Written informed consent was obtained from the patient for publication of this case report and any accompanying images. The patient provided consent specifically for the publication of clinical information and imaging findings. No personally identifiable information is included in the published images.
Conflict-of-interest statement: All authors declare no conflicts of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Min Hyun Kim, MD, Division of Colon and Rectal Surgery, Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea. mhjerrykim@gmail.com
Received: June 11, 2025
Revised: July 4, 2025
Accepted: August 13, 2025
Published online: October 26, 2025
Processing time: 123 Days and 1.2 Hours
Revised: July 4, 2025
Accepted: August 13, 2025
Published online: October 26, 2025
Processing time: 123 Days and 1.2 Hours
Core Tip
Core Tip: We report here the first case of spontaneous colonic transection in a patient with high microsatellite instability colon cancer who achieved pathologic complete response after long-term pembrolizumab therapy. Despite no residual tumor on imaging or pathology, intraoperative findings revealed a discontinuity of the bowel at the original tumor site. Immune-mediated remodeling can compromise bowel integrity and may not be apparent on imaging. Clinicians should consider potential anatomic changes when planning surgery in patients treated with immunotherapy, even in the context of a complete response.