Intestinal Behcet's disease with severe pulmonary arterial involvement mimicking ulcerative colitis

Background: Behcet’s disease (BD) is a chronic inflammatory systemic vasculitic disorder and affects multiple organ systems. Although the prevalence of the disease is high in Turkey, intestinal involvement is rare. Objective: To report a case highlighting the high risk of mortality as a result of vascular involvement in BD, and suggest classification as a differential diagnosis in intestinal disease and inflammatory bowel disease (IBD). Method: We report a case of BD in a patient who had symptoms of IBD and was misdiagnosed as having IBD, but later diagnosed as having BD with aneurisms on pulmonary vessels. Results: A 23-year-old woman was diagnosed with and followed for ulcerative colitis (UC) by another center for one year. She was admitted to hospital with bloody diarrhea, abdominal pain, and weight loss symptoms. There were erythema nodosum-like lesions (ENLL) at pretibial sites and pustular lesions on her upper extremities. Colonoscopy showed nonspecific ulcerations on the colon and terminal ileum and the histopathology was nonspecific. During this period she complained of hemoptysis. Computed tomography (CT) of her thorax showed vascular dilatations in the parenchyma of the lung. CT angiography showed multiple pulmonary arterial aneurisms. She reported a history of recurrent oral aphthous and genital ulcers. A pathergy test was positive and she was diagnosed as having BD with severe pulmonary arterial involvement. Prednisolone (1 mg/kg/day), and cyclophosphamide (750 mg/m 2 /month) was administered. At the end of the second week of treatment she showed significant clinical improvement. Conclusion: IBD symptoms and signs may be the first presentation of BD. Because of the high risk of mortality as a result of vascular involvement, BD must be classified as a differential diagnosis in intestinal disease and IBD.