Perforated acute appendicitis on computed tomography revealing underlying tuberculosis

Tuberculous appendicitis is an extremely rare manifestation of gastrointestinal tuberculosis and is often clinically and radiologically indistinguishable from conventional acute appendicitis. We report the case of a 27-year-old man who presented with fever and pain in the right lower quadrant. Contrast-enhanced computed tomography revealed an enlarged appendix with an appendicolith, a distal wall defect, and periappendiceal abscess formation, consistent with perforated acute appendicitis. Laparoscopic appendectomy was performed. Histopathological examination revealed acute gangrenous appendicitis with multiple caseating granulomas predominantly involving the mucosa and submucosa. Although acid-fast bacilli staining was negative, the interferon-gamma release assay was positive, and chest computed tomography revealed pulmonary nodular lesions, supporting the clinical diagnosis of tuberculosis. Anti-tuberculous therapy was initiated. Isolated appendiceal tuberculosis lacks specific imaging features and is frequently indistinguishable from typical acute appendicitis, particularly when complicated by an appendicolith or perforation. This case highlights the importance of considering tuberculosis when granulomatous inflammation is identified on histopathology and performing a systemic evaluation even in patients presenting with typical features of acute appendicitis.