Anal Tuberculosis: Diagnostic Challenges and Ambiguities with Crohn's Disease: A case report

Abstract Tuberculosis is an infectious disease caused by mycobacteria within the tuberculosis complex. Anal tuberculosis is a rare and often underdiagnosed condition, accounting for approximately 1% of gastrointestinal tuberculosis cases. We present the case of a 40-year-old male with anal tuberculosis, initially managed under the suspicion of Crohn’s disease and treated with a combined regimen of an immunosuppressant (azathioprine) and an anti-TNF agent (infliximab). Owing to the persistence of symptoms, a GeneXpert assay performed on the anal fistula, designed to detect the DNA of acid-fast bacilli, returned a positive result.  Infection in the anorectal region can occur through ingestion of sputum containing the bacilli, direct inoculation via anal skin fissures, or, more rarely, hematogenous dissemination.  Ziehl-Neelsen staining for acid-fast bacilli is not always definitive. Histological examination plays a key role in identifying epithelioid giant-cell granulomas and caseous necrosis. Culturing on liquid or solid media takes a prolonged period, which is incompatible with the need for timely treatment. Therefore, the GeneXpert MTB/RIF assay is preferred for its high sensitivity, specificity, speed, and ease of use. The diagnosis of tuberculosis is often complex and relies on a combination of clinical, radiological, histological, and biological evidence, as well as a positive response to antituberculous therapy. Email addresses aminaachraibi@gmail.com, sofiafellah96@gmail.com, keddaif@gmail.com, doae.arjoudane@gmail.com, Mr_bennani@outlook.com, najoua1497.bn@gmail.com, hamza.goura@um5s.net.ma, benlahlouyassine@gmail.com benaissaelmostafa2@gmail.com, mariamachadli@gmail.com