A Rare Presentation of Abdominal Pain: Idiopathic Mesenteric Phlebosclerosis

Abstract

Purpose: Idiopathic mesenteric phlebsclerosis (IMP) is a rare gastrointestinal disorder that results in chronic mesenteric ischemia through non-inflammatory, non-thrombotic stenosis of the mesenteric veins. It was first proposed by Iwashita in 2003. To date, there have been less than 100 reported cases worldwide, mostly in Japan, but also described in Hong Kong, Korea, and Taiwan. We would like to present the first case reported in the U.S. A 57-year old female, originally from southern China, with a history of hyperlipidemia presented with increasing postprandial right lower quadrant pain for three weeks. She denied any other associated symptoms. An initial computerized tomography (CT) scan of the abdomen revealed cecal and ascending colon wall thickening with mild right lower quadrant fat stranding suggesting an infectious colitis. Initially, the calcifications in the small mesenteric veins and their intramural colonic branches were not appreciated. Stool studies and labs were unrevealing. A colonoscopy was performed and revealed congested mucosa with a dusky appearance extending from the cecum to mid transverse colon. Pathology revealed mild basement membrane thickening and there was hyaline fibrosis of small vessels in the lamina propria. The patient improved clinically and underwent a follow up colonoscopy six months later, which again demonstrated dusky appearing mucosa from the cecum to the proximal transverse colon and pathology showed colonic mucosa with increased collagen deposition in the basement membrane and lamina propria. A repeat abdominal CT scan demonstrated persistent bowel wall thickening of the cecum, ascending colon and terminal ileum with multiple calcifications within the distal right colonic venous cascades and small mesenteric veins suggestive of IMP. She was discharged with follow up in gastroenterology. IMP is a rare clinical entity that has only been reported in Asia, whose diagnosis is based on clinical history and hallmark radiographic findings. On imaging, there is involvement of the right hemicolon, with classic multiple threadlike venous calcifications in the colonic wall and small mesenteric vessels. Endoscopically, IMP is characterized by dark purplish mucosa, colonic ulcerations and edematous mucosa. Histologically, one observes submucosal fibrosis and increased collagen deposition in IMP. The pathogenesis remains poorly understood, but diabetes, hyperlipidemia, liver cirrhosis, autoimmune disorders and herbal supplements have all been implicated as potential causes. Likewise, the natural history of IMP is unknown. However, in a case series of 21 patients, 13 ultimately underwent subtotal colectomy. Surgery may be considered for persistent symptoms or obstruction.