SHM Converge Scientific Abstract ePoster Gallery-When Tests Lie: Navigating the Path to Tuberculosis Diagnosis

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This poster presents a 76-year-old man with hypertension and recent travel to India who developed subacute dyspnea, low-grade fevers, night sweats, and chronic cough. He was first treated for community-acquired pneumonia without improvement. Imaging later showed a large left pleural effusion, centrilobular nodules, tree-in-bud opacities, and mediastinal lymphadenopathy, raising concern for infection or malignancy.<br /><br />Despite strong clinical suspicion, multiple tuberculosis tests were initially negative. During a second hospitalization, AFB sputum smears, pleural fluid testing, MTB PCR, QuantiFERON Gold, and extensive fungal, bacterial, and autoimmune workup were all unrevealing. Only after a third hospitalization and bronchoscopy did bronchoalveolar lavage fluid become positive for AFB staining and Mycobacterium tuberculosis PCR. He was then started on rifampin, isoniazid, pyrazinamide, and ethambutol and discharged with public health follow-up.<br /><br />The case highlights important limitations of TB diagnostics. The poster summarizes that interferon-γ release assays and nucleic acid amplification tests have good but imperfect sensitivity and specificity, while culture remains definitive but can take weeks on solid media. Molecular testing is faster, but negative results do not exclude disease. TB can also clinically mimic pneumonia, fungal infection, or lung cancer, delaying diagnosis.<br /><br />Key learning points are that hospitalists should maintain a high index of suspicion for TB even when early testing is negative and recognize how cognitive biases may contribute to diagnostic error. Early consideration of bronchoscopy and repeat testing may be necessary when symptoms and imaging remain concerning.

Asset Subtitle

Annalise McDonald

Meta Tag

Author List Annalise McDonald, Helpees Guirguis, Sarah F. Horman

Category Clinical Vignettes

Concept Tuberculosis

Concept Sputum Acid-Fast Bacilli Test

Concept Bronchoscopy

Concept Bronchoalveolar Lavage

Concept Pleural Fluid Analysis

Distinguished Non-Finalist

Presenter Organization UC San Diego Health

Presenting Author Annalise McDonald

Track Adult

Keywords

tuberculosis

AFB

bronchoscopy

pleural effusion

tree-in-bud opacities

mediastinal lymphadenopathy

Mycobacterium tuberculosis

QuantiFERON Gold

diagnostic limitations

rifampin isoniazid pyrazinamide ethambutol

Tuberculosis

Sputum Acid-Fast Bacilli Test

Bronchoscopy

Bronchoalveolar Lavage

Pleural Fluid Analysis