Mesenteric inflammatory veno-occlusive disease occurring during the course of ulcerative colitis: a case report

BACKGROUND: Mesenteric inflammatory veno-occlusive disease (MIVOD) is difficult to diagnose because of its rarity, nonspecific clinical findings, and frequent confusion with other diseases including inflammatory bowel disease. This report presents a very rare case of MIVOD that occurred during the course of ulcerative colitis (UC). CASE PRESENTATION: A 32-year-old man, who had been diagnosed with UC at the age of 29 and was in remission maintained by oral administration of 5-aminosalicylic acid (5-ASA), showed exacerbation of diarrhea and was admitted to the hospital. Since it was deemed an exacerbation of UC, intravenous steroid therapy and oral administration of tacrolimus were initiated, but his condition continued to worsen. Abdominal computed tomography (CT) was performed and showed intraperitoneal free air, leading to a diagnosis of gastrointestinal perforation and the performance of emergency surgery (subtotal colectomy and ileostomy). Histopathological examination of the resected colon of the patient showed mucosal inflammatory findings that were not typical of UC, including multiple organized thrombi with recanalization in the veins existing in the submucosal layer to the subserosal layer and an increased infiltration of inflammatory cells. These findings led to the pathological diagnosis of MIVOD. CONCLUSION: We report a very rare case in which MIVOD occurred during the course of UC.