Splenic Tuberculosis in a Patient With Crohn's Disease Receiving Anti-tumor Necrosis Factor-α (TNF-α) Therapy: A Case Report.

Splenic tuberculosis is a rare manifestation of extrapulmonary tuberculosis, particularly presenting as isolated splenic disease. This study reports a 36-year-old man with Crohn's disease on adalimumab who presented with constitutional symptoms and multiple splenic nodules on imaging. Although initial latent tuberculosis screening using QuantiFERON in 2023 was negative, seroconversion was documented at admission. It should be noted that interferon-gamma release assays (IGRAs) (QuantiFERON) detect only Mycobacterium tuberculosis complex sensitization and do not detect non-tuberculous mycobacteria (NTM) or other bacterial pathogens; therefore, negative IGRA results do not exclude alternative mycobacterial or bacterial splenic disease. Image-guided splenic biopsy confirmed Mycobacterium tuberculosis with rifampicin susceptibility and caseating granulomas. Following adalimumab discontinuation and initiation of antituberculous therapy (isoniazid, rifampicin, pyrazinamide, and ethambutol {HRZE}), clinical remission was rapid and complete. This case emphasizes that splenic tuberculosis should remain in the differential diagnosis of patients receiving anti-tumor necrosis factor-α (TNF-α) agents, even after prior negative screening, and that early diagnosis via biopsy and rapid molecular testing (GeneXpert) significantly improves outcomes. Sustained vigilance and multidisciplinary coordination between gastroenterology, infectious diseases, and diagnostic imaging are essential in managing suspected tuberculosis in this high-risk population.