Idiopathic mesenteric phlebosclerosis.
A 67-year-old woman presented to the gastroenterology outpatient department with a history of chronic intermittent mild lower abdominal pain and nausea. She was diagnosed as having mild hypertension, but she had no previous cardiovascular or gastrointestinal problems. She had a history of using traditional Chinese medicine for 10 years. The result of an immunochemical faecal occult blood test is positive. Colonoscopy revealed a purple-blue mucosa, multiple ulcers and significant rigidity along the intestinal wall extending from the cecum to the hepatic flexure (Figure 1A). The abdominal computed tomography scan showed colonic wall thickenings with calcification of the superior mesenteric vein in the ascending colon (Figure 1B). On the basis of the clinical and radiographic findings, we diagnosed the patient as having idiopathic mesenteric phlebosclerosis (IMP). After withdrawal from traditional Chinese medicine, her symptoms and colonoscopy findings improved gradually. IMP is a rare chronic intestinal ischaemia, caused by calcified peripheral mesenteric veins and considerable rigidity along the intestinal wall. Long-term exposure to various types of herbal medicine and traditional Chinese medicines, including geniposide from Gardenia jasminoides, is significantly associated with IMP. Geniposide is hydrolysed to genipin by intestinal bacterial flora. The absorbed genipin spontaneously reacts with primary amines and proteins in the superior mesenteric plasma, which forms blue particles and causes characteristic pigmentation, sclerosis and calcifications of the superior mesenteric vein. Almost all patients with IMP have been reported from Asian countries, such as Japan, Taiwan and mainland China. One case was reported in Canada; however, the patient was of Taiwanese decent. Most patients present with gastrointestinal symptoms, including abdominal pain, nausea, vomiting, bloating, diarrhoea and melena. Approximately 20% of patients are asymptomatic and found incidentally. Although patients with asymptomatic and mild IMP need careful observation, those complicated with colonic obstruction or perforation require surgical procedures. Therefore, when these characteristic radiographic and/or colonoscopic findings are present, clinicians should check the patient’s use of oral medications and consider withdrawing traditional Chinese medicines.