Lee JS, Kim EY, Kwon JG, Bae JH, Kim M, Yang CS, Yu SH, Cho CH, Jo HH. Idiopathic myointimal hyperplasia of mesenteric veins mimicking steroid-refractory ulcerative colitis: A case report. World J Gastroenterol 2026; 32(47): 122949 [DOI: 10.3748/wjg.122949]
Corresponding Author of This Article
Hyeong Ho Jo, MD, Assistant Professor, Department of Internal Medicine, Daegu Catholic University School of Medicine, 33 Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, South Korea. johh0205@naver.com
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Gastroenterology & Hepatology
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case-report
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Lee JS, Kim EY, Kwon JG, Bae JH, Kim M, Yang CS, Yu SH, Cho CH, Jo HH. Idiopathic myointimal hyperplasia of mesenteric veins mimicking steroid-refractory ulcerative colitis: A case report. World J Gastroenterol 2026; 32(47): 122949 [DOI: 10.3748/wjg.122949]
World J Gastroenterol. Dec 21, 2026; 32(47): 122949 Published online Dec 21, 2026. doi: 10.3748/wjg.122949
Idiopathic myointimal hyperplasia of mesenteric veins mimicking steroid-refractory ulcerative colitis: A case report
Ju Seok Lee, Eun Young Kim, Joong Goo Kwon, June Hwa Bae, Mina Kim, Chun-Seok Yang, Seong Ho Yu, Chang-Ho Cho, Hyeong Ho Jo
Ju Seok Lee, Eun Young Kim, Joong Goo Kwon, June Hwa Bae, Mina Kim, Hyeong Ho Jo, Department of Internal Medicine, Daegu Catholic University School of Medicine, Daegu 42472, South Korea
Chun-Seok Yang, Seong Ho Yu, Department of Colorectal Surgery, Daegu Catholic University School of Medicine, Daegu 42472, South Korea
Chang-Ho Cho, Department of Pathology, Daegu Catholic University School of Medicine, Daegu 42472, South Korea
Author contributions: Lee JS and Jo HH conceived the study; Lee JS collected the clinical data and drafted the manuscript; Kim EY, Kwon JG, Bae JH, Kim M, Yang CS, Yu SH, Cho CH, and Jo HH contributed to data interpretation and critically revised the manuscript; Yang CS and Yu SH performed the surgery; Cho CH interpreted the pathological findings. All authors read and approved the final manuscript.
AI contribution statement: Portions of this manuscript were edited with the assistance of ChatGPT (OpenAI) solely for language refinement and improvement of grammar and clarity. The authors carefully reviewed, verified, and approved all AI-assisted outputs. AI tools were not used to generate original scientific data, perform independent scientific analyses, or draw scientific conclusions. The authors take full responsibility for the integrity, accuracy, and scientific content of the manuscript.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
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).
Corresponding author: Hyeong Ho Jo, MD, Assistant Professor, Department of Internal Medicine, Daegu Catholic University School of Medicine, 33 Duryugongwon-ro 17-gil, Nam-gu, Daegu 42472, South Korea. johh0205@naver.com
Received: May 8, 2026 Revised: July 21, 2026 Accepted: August 10, 2026 Published online: December 21, 2026 Processing time: 177 Days and 19.4 Hours
Abstract
BACKGROUND
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare, non-thrombotic venous occlusive disease that causes chronic intestinal ischemia and frequently mimics inflammatory bowel disease, particularly ulcerative colitis. Because clinical, endoscopic, and radiologic findings are nonspecific, IMHMV is often misdiagnosed, leading to delayed definitive treatment.
CASE SUMMARY
A 65-year-old man with a history of living-donor liver transplantation presented with a 6-month history of watery diarrhea and abdominal pain. He was receiving tacrolimus and mycophenolate mofetil for immunosuppression. Colonoscopy demonstrated continuous colitis extending from the mid-transverse colon to the rectum, and mucosal biopsies showed only nonspecific chronic inflammation. Despite treatment with mesalazine, corticosteroids, and filgotinib, the patient showed progressive clinical deterioration and developed massive hematochezia requiring emergent open subtotal colectomy with end transverse colostomy and rectal stump preservation. Histopathologic examination of the resected specimen revealed marked myointimal hyperplasia of mesenteric veins with near-complete luminal obliteration and subendothelial fibrin deposition, while arterial structures were preserved, confirming IMHMV. Postoperatively, inflammation recurred in the rectal stump and improved with topical mesalazine therapy.
CONCLUSION
IMHMV should be considered in patients with steroid-refractory colitis and nonspecific biopsy findings. This case highlights the diagnostic limitations of mucosal biopsy, the importance of histopathologic confirmation, and the need for careful interpretation of postoperative rectal inflammation, in which diversion colitis and underlying inflammatory bowel disease may overlap.
Core Tip: Idiopathic myointimal hyperplasia of mesenteric veins is a rare venous occlusive disease that can closely mimic ulcerative colitis and lead to misdiagnosis. This case demonstrates progressive steroid-refractory colitis unresponsive to medical therapy, ultimately requiring surgery for definitive diagnosis. Postoperative rectal inflammation created a diagnostic dilemma between diversion colitis and possible underlying inflammatory bowel disease. This report highlights the importance of considering vascular etiologies in refractory colitis and cautiously interpreting postoperative endoscopic findings.
