Recommended Citation
Etukudoh B. Smear-Negative Pulmonary Tuberculosis Masquerading as Complicated Parapneumonic Effusion in an Infliximab-Treated Patient. Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Abstract
Background/Significance:
Tuberculosis (TB) incidence in the United States remains low at approximately 3 cases per 100,000 persons annually; however, patients receiving tumor necrosis factor-alpha (TNF-α) inhibitors are at significantly increased risk of reactivation disease due to impaired granuloma maintenance. Anti-TNF– associated TB frequently presents atypically and may be smear- and PCR-negative, often mimicking bacterial pneumonia or malignancy. Diagnostic delay is common, particularly in cases involving pleural effusion.
Description:
A 66-year-old male with relapsing polychondritis on infliximab presented with pleuritic chest pain and acute hypoxic respiratory failure. Imaging revealed right upper lobe consolidation with a loculated pleural effusion. Pleural fluid was exudative with low glucose and elevated lactate dehydrogenase; adenosine deaminase was mildly elevated (47 U/L). Serial sputum acid-fast bacilli (AFB) smears, Mycobacterium tuberculosis PCR, bronchoscopy with bronchoalveolar lavage, fungal studies, and cytology were negative. He underwent chest tube placement and intrapleural fibrinolytic therapy for presumed complicated parapneumonic effusion, with transient clinical improvement. Airborne precautions were maintained given persistent diagnostic uncertainty. Five days after discharge, he represented with recurrent pleuritic pain and interval enlargement of a pleural-based right upper lobe mass-like opacity. CT-guided lung biopsy demonstrated necrotizing granulomatous inflammation highly suggestive of pulmonary TB. Empiric RIPE therapy was initiated and later modified due to drug-induced hepatotoxicity. Follow-up imaging showed radiographic improvement.
Discussion:
TNF-α blockade predisposes patients to smear-negative and atypical TB presentations. Pleural TB may yield negative AFB and PCR testing, and mildly elevated adenosine deaminase levels overlap with parapneumonic effusions, complicating diagnosis. Bronchoscopy may have limited yield for peripheral pleural-based lesions. In high-risk immunocompromised patients with progressive upper-lobe disease, early tissue diagnosis should be strongly considered when noninvasive studies are unrevealing. Maintenance of airborne precautions during evaluation is essential, as smear-negative TB may remain transmissible. While empiric anti-tubercular therapy may be appropriate in selected cases, potential toxicity, including hepatotoxicity, requires careful monitoring. This case highlights the importance of heightened suspicion.
Presentation Notes
Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Full Text of Presentation
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Document Type
Poster
Open Access
Available to all.
Smear-Negative Pulmonary Tuberculosis Masquerading as Complicated Parapneumonic Effusion in an Infliximab-Treated Patient
Background/Significance:
Tuberculosis (TB) incidence in the United States remains low at approximately 3 cases per 100,000 persons annually; however, patients receiving tumor necrosis factor-alpha (TNF-α) inhibitors are at significantly increased risk of reactivation disease due to impaired granuloma maintenance. Anti-TNF– associated TB frequently presents atypically and may be smear- and PCR-negative, often mimicking bacterial pneumonia or malignancy. Diagnostic delay is common, particularly in cases involving pleural effusion.
Description:
A 66-year-old male with relapsing polychondritis on infliximab presented with pleuritic chest pain and acute hypoxic respiratory failure. Imaging revealed right upper lobe consolidation with a loculated pleural effusion. Pleural fluid was exudative with low glucose and elevated lactate dehydrogenase; adenosine deaminase was mildly elevated (47 U/L). Serial sputum acid-fast bacilli (AFB) smears, Mycobacterium tuberculosis PCR, bronchoscopy with bronchoalveolar lavage, fungal studies, and cytology were negative. He underwent chest tube placement and intrapleural fibrinolytic therapy for presumed complicated parapneumonic effusion, with transient clinical improvement. Airborne precautions were maintained given persistent diagnostic uncertainty. Five days after discharge, he represented with recurrent pleuritic pain and interval enlargement of a pleural-based right upper lobe mass-like opacity. CT-guided lung biopsy demonstrated necrotizing granulomatous inflammation highly suggestive of pulmonary TB. Empiric RIPE therapy was initiated and later modified due to drug-induced hepatotoxicity. Follow-up imaging showed radiographic improvement.
Discussion:
TNF-α blockade predisposes patients to smear-negative and atypical TB presentations. Pleural TB may yield negative AFB and PCR testing, and mildly elevated adenosine deaminase levels overlap with parapneumonic effusions, complicating diagnosis. Bronchoscopy may have limited yield for peripheral pleural-based lesions. In high-risk immunocompromised patients with progressive upper-lobe disease, early tissue diagnosis should be strongly considered when noninvasive studies are unrevealing. Maintenance of airborne precautions during evaluation is essential, as smear-negative TB may remain transmissible. While empiric anti-tubercular therapy may be appropriate in selected cases, potential toxicity, including hepatotoxicity, requires careful monitoring. This case highlights the importance of heightened suspicion.
Affiliations
Advocate Lutheran General Hospital