[A Case of Small Bowel Diffuse Large B-cell Lymphoma Mimicking Crohn's Disease].

A 66-year-old male with dyspepsia and weight loss was referred to our hospital for evaluation. On laboratory examination, anti-saccharomyces cerevisiae (ASCA)-IgA was positive and iron deficiency anemia was present. PET/CT and abdominal CT scan images showed multiple small bowel segmental wall thickening and inflammation. Capsule endoscopy images showed multiple small bowel ulcerative lesions with exudates. Based on laboratory test results and imaging studies, the patient was diagnosed with Crohn's disease and treated with prednisolone and 5-aminosalicylic acid (5-ASA). However, the patient underwent second operation due to small bowel perforation within 2 month after initiation of treatment. Pathology report of the resected specimen was compatible to primary small bowel diffuse large B cell lymphoma and pertinent treatment was given to the patient after recovery. Herein, we describe a case of primary small bowel diffuse large B cell lymphoma that was mistaken for Crohn's disease.