Focal myointimal hyperplasia of mesenteric veins is associated with previous trauma in surgical specimens

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood disease that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. This disease is often confused with chronic idiopathic inflammatory bowel disease clinically, and pathologists may miss the diagnosis unless elastin stains are performed because diseased veins may readily be mistaken for arteries. The etiology of IMHMV is unclear, but a traumatic pathomechanism resulting in arterialization of the veins has been proposed. Review of bowel resection specimens (n=68) for non-neoplastic disease within a 1-year period in patients younger than 50 years of age revealed 10 cases with focal mesenteric vein myointimal hyperplasia. Significantly more cases with focal myointimal hyperplasia of mesenteric veins (MHMV) were associated with pre-resection trauma to the involved bowel segment (5/11 vs. 5/57; p=0.0016). A significant association of MHMV with pre-resection trauma supports the hypothesis that idiopathic myointimal hyperplasia of the mesenteric veins may be the result of trauma through torsion/stretching of the sigmoid colon and, subsequently, increased mesenteric venous pressure through arterialization.