Supplemental Material for: Diagnostic Challenge of Crohn’s Disease in a Patient with Clinically Diagnosed Pulmonary Tuberculosis: A Case Report

Intestinal biopsy specimens demonstrated severe chronic active inflammation;<i>Mycobacterium tuberculosis</i>polymerase chain reaction and acid-fast bacillus staining were negative. During a standard 6-month antituberculosis regimen, the patient developed intermittent abdominal pain and recurrent vomiting. Repeat chest computed tomography showed resolution of the pulmonary nodules, whereas colonoscopy after 5 months demonstrated persistent longitudinal ulcers, pseudopolyps, skip areas, and stricturing from the terminal ileum to the rectum.

Histopathology showed severe chronic active colitis with cryptitis, crypt abscesses, tissue eosinophilia, and rare non-necrotizing granulomas. A Crohn’s Disease Activity Index score of 229 and the overall clinicopathologic findings favored ileocolonic stricturing CD. Mesalamine and ustekinumab were initiated, with resolution of abdominal pain and vomiting, weight gain, and a decline in fecal calprotectin from 1,740 to 320 µg/g.

Follow-up colonoscopy approximately 1 year later (Week 48 of ustekinumab) showed resolution of the previous extensive ulceration and friability, with pseudopolyposis and ileocecal valve narrowing. Biopsies demonstrated focal mild cecal cryptitis without active inflammation in the remaining sampled colonic segments or distal terminal ileum.</p><p dir="ltr"><b>Conclusion</b></p><p dir="ltr">This case underscores the diagnostic challenge of distinguishing Crohn’s disease from gastrointestinal tuberculosis in a patient with clinically diagnosed pulmonary tuberculosis.

Persistent ileocolonic inflammation despite adequate anti-tuberculosis therapy, repeatedly negative intestinal tuberculosis studies, and endoscopic and histopathologic features favoring Crohn’s disease should prompt timely diagnostic reassessment and appropriate disease-specific treatment.</p>