Idiopathic Myointimal Hyperplasia of the Mesenteric Veins.

Case Report

A 65-year-old man with no significant past medical history was admitted to an outside hospital with 1.5 months of crampy, lower abdominal pain associated with rectal urgency and tenesmus. Initial computed tomography showed thickening of his rectosigmoid and mid to distal descending colon; follow-up colonoscopy revealed inflammation of the affected areas with focal lamina propria vascular congestion and sloughing epithelium in the rectosigmoid colon. A course of antibiotics followed by a course of oral steroids did not improve his symptoms.

He was admitted with worsening pain. Initial laboratory studies were unremarkable except for a positive Clostridium difficile polymerase chain reaction, although oral vancomycin did not lead to improvement. Computed tomography showed similar findings with pericolonic inflammation. Subsequent flexible sigmoidoscopy revealed cobblestoning and skip inflammation of the mucosa in the sigmoid colon with rectal ulcers concerning for Crohn’s disease, but his symptoms worsened despite aggressive treatment with steroids and mesalamine. Biopsies returned revealing dilated mucosal capillaries without active colitis. His symptoms continued to worsen, so a repeat sigmoidoscopy 9 days later demonstrated stricturing of the sigmoid colon and worsening of the mucosal ulceration (Figure 1). Repeat biopsies in the rectosigmoid colon showed severe ischemic injury concerning for idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV). The patient was recommended for surgical resection multiple times. Soon thereafter he developed a perforation of the sigmoid colon and underwent an emergent resection with a left end colostomy. Final pathology revealed muscular thickening of the intramural veins consistent with IMHMV (Figure 2).

Figure 1

Sigmoid colon demonstrating severely friable, ulcerated, and erythematous mucosa.

Figure 2

Final histopathology of colon at 20x magnification demonstrating muscular thickening of the intramural veins (white arrow) with histologically unremarkable accompanying arteries (black arrow).

Idiopathic myointimal hyperplasia of the mesenteric veins is a rare disease entity typically affecting young, healthy males often initially misdiagnosed as inflammatory bowel disease because of the similarity in patient demographics, clinical symptoms, and endoscopic findings. However, biopsies usually reveal nonspecific ischemic changes.1,2 Usually the final diagnosis is made in histopathological analysis after surgical resection, which reveals nonthrombotic and noninflammatory occlusion of the mesenteric veins secondary to myointimal hyperplasia.3 One report has been published in which the diagnosis was made preoperatively through endoscopic biopsy; our case was similarly diagnosed, suggesting that a preoperative diagnosis may be routinely possible if there is a high degree of suspicion for IMHMV.4 Recurrences have not been reported after surgical resection, raising the idea that it is likely curative. Because our patient’s sigmoid perforation was likely related to IMHMV, early treatment may be of benefit to reduce morbidity.

Disclosures

Author contributions: AD Patel, Y. Schneider, M. Saumoy, C. Maltz, and H. Yeo wrote the manuscript. J. Jessurun provided and analyzed the pathological images. D. Wan supervised the manuscript writing and is the article guarantor.

Financial disclosure: None to report.

Informed consent was obtained for this case report.

Previous Presentation: This case was presented at the ACG Annual Scientific Meeting; October 16-21, 2105; Honolulu, Hawaii.