Case Report: Idiopathic myointimal hyperplasia of mesenteric veins mimicking inflammatory bowel disease: a case report with literature review.

BACKGROUND: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare and poorly understood disease, typically affecting the rectosigmoid colon of young, otherwise healthy men. Clinically, it is often mistaken for inflammatory bowel disease, as biopsies show ischemic mucosal changes without classic inflammatory features. Surgical resection is both diagnostic and curative, although the etiology of IMHMV remains unclear.

CASE PRESENTATION: We report the case of a female patient with IMHMV involving the right hemicolon, concomitant with Clostridium difficile infection. Her symptoms persisted despite targeted treatment for C. difficile. She subsequently underwent a laparoscopic right hemicolectomy, which revealed mesenteric vein occlusion due to myointimal hyperplasia, confirmed by elastin staining and desmin immunohistochemistry. Histopathological examination established the diagnosis of IMHMV. The patient recovered well postoperatively, with no recurrence observed during follow-up.

CONCLUSION: This is the first documented case of IMHMV involving the right hemicolon and complicated by Clostridium difficile infection. In addition, we reviewed 82 previously reported cases from 1991 to 2024, highlighting the clinical, imaging, and pathological characteristics of IMHMV. Recognition of this rare entity is essential to avoid unnecessary pharmacotherapy, prevent misdiagnosis as inflammatory bowel disease, and facilitate timely surgical management.