Question: A previously healthy 43-year-old woman presented with epigastric pain and intermittent postprandial vomiting for 1 year. The patient denied any fever, night sweats, extraintestinal symptoms, and perianal disease. Physical examination was unremarkable. Initial laboratory values were within normal limits except for increased erythrocyte sedimentation rate (46 mm/h) and positive fecal calprotectin. Ileocolonoscopy revealed erosions in the terminal ileum. Biopsy specimens showed unspecific alterations with acute and chronic inflammation. Computed tomography enterography showed circumferential thickening and enhancement of the multiple segmental small intestinal walls, with luminal stricture and enlarged peripheral lymph nodes (Figure A). Subsequent interferon-γ release assay for Mycobacterium tuberculosis was negative and no tuberculous lesions were found on a computed tomography scan of the chest. What is the most likely diagnosis? See the Gastroenterology web site () for more information on submitting your favorite image to Clinical Challenges and Images in GI. Owing to the symptoms of mechanical obstruction and diagnostic uncertainty, a decision was made to undertake a surgical approach. Laparoscopy confirmed 8 segments of thickened intestinal wall between 5 and 200 cm proximal to the ileocecal valve, accompanied by numerous white, miliary nodules on the mesenterium and intestinal wall (Video). Focally stenosis was found (Figure B) and partial intestinal resection was obtained followed by end-to-side anastomosis. Macroscopic examination showed a circumferential ulcer (Figure C, arrows). Pathology revealed numerous caseating granulomas throughout intestinal tissue, characterized by confluent granuloma, large granuloma, and granuloma with surrounding cuffing lymphocytes (Figure D). Additionally, the results of acid-fast staining (Figure E, circle) and polymerase chain reaction testing for M tuberculosis were positive. Hence, a firm diagnose of intestinal tuberculosis was made. HIV testing was negative. The patient is on a 1-year course of antituberculosis treatment with good response. Multiple diagnostic models have been developed regarding the differentiation of intestinal tuberculosis from Crohn’s disease.1He Y. Zhu Z. Chen Y. et al.Development and validation of a novel diagnostic nomogram to differentiate between intestinal tuberculosis and Crohn's disease: a 6-year prospective multicenter study.Am J Gastroenterol. 2019; 114: 490-499Crossref PubMed Scopus (33) Google Scholar An interferon-γ release assay is the most commonly used tool. Although this assay has very high specificity (>95%), the sensitivity is only approximately 80%, as in our case.2Pai M. Zwerling A. Menzies D. Systematic review: T-cell-based assays for the diagnosis of latent tuberculosis infection: an update.Ann Intern Med. 2008; 149: 177-184Crossref PubMed Scopus (1150) Google Scholar Persons with tuberculosis in high incidence countries (like China) often have advanced disease and are likely to be malnourished or infected with HIV. Anergy owing to advanced disease (which may be applicable to our patient), malnutrition, and HIV-associated immune suppression may decrease the sensitivity of interferon-γ release assays. Hence, it is a challenge to make the differential diagnosis between intestinal tuberculosis and Crohn’s disease. Multiple segmental involvement at small intestine, especially with a normal-appearing ileocecal valve are very unusual in intestinal tuberculosis.3Bae J.H. Park S.H. Ye B.D. et al.Development and validation of a novel prediction model for differential diagnosis between Crohn's disease and intestinal tuberculosis.Inflamm Bowel Dis. 2017; 23: 1614-1623Crossref PubMed Scopus (24) Google Scholar It is frequently misdiagnosed as Crohn’s disease preoperatively. As seen in this patient, exploratory abdominal surgery was usually required for the final diagnosis. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI3MmVmM2EzMDEyNjRiZGU1NmI2Y2JmZDZiZGQ5NTliOSIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjcwOTExMjExfQ.isWS2Gk2qOguY5qIEWij4OJBJJuDXzRct5FoY4d49ZTUqfOvNyjzd1PuZwASlAVJpvWR_qEgLYpzjYhehlCMN4gTvH8mTzg_UwEDnoLexdCTsH7vGKnT_xuoZGKwhtNfM0gn4I4Egq4qkollG2UzWKHjesnMvmGKA4ConZhyqLtNlvkqdKFhWR5lW_6KLRIGLvHJqjRC6CcZlJyw1eaIBWQIyTRIqRLoQptMipd4z30ZuvX4XeDx6KNv8KIovkFSqXtDAPflPunRAUETprl6ZY0Gsakyh79bWf9_SLhN1jIiQnIqC_4AAE-EolCxqQA-zFICCCfw8QlB48Y4ITISHA Download .mp4 (16.47 MB) Help with .mp4 files Video