B63-17 Unilateral Lung “White Out” in an Infant: Unusual Cause by an Old Nemesis

Abstract Endobronchial tuberculosis (EBTB) is a rare and challenging form of tuberculosis (TB) that involves the tracheobronchial tree, characterized by granulomatous inflammation within the airways, which can lead to airway obstruction, bronchial stenosis, and post obstructive atelectasis. Diagnosing EBTB is especially difficult in young children and infants, where clinical and radiographic findings often overlap with other respiratory conditions and oncologic conditions, particularly in countries with low TB prevalence. A previously healthy, fully immunized, 10-month-old male presented to an outside hospital emergency department with a one-week history of mild intermittent cough and fever. In triage, he experienced a generalized, non-focal febrile seizure lasting 3 minutes with apnea. Parents denied all other acute concerns. Patient was put on high-flow nasal cannula (HFNC) for the apnea but was not in significant distress. Chest x-ray (CXR) on presentation showed complete opacification of left hemithorax. WBC was elevated at 22.7, CRP was elevated at 6.83. VBG and procalcitonin were within normal limits. Respiratory pathogen panel was negative. Further imaging including a chest computerized tomography (CT) showed a subcarinal lymph node extending into and occluding the left mainstem bronchus with post obstructive atelectasis. Interventional bronchoscopy was performed to visualize and remove the central airway obstruction. Pathology and laboratory studies identified the lesion as a caseating granuloma negative for organisms/fungi. Tests later revealed a positive QuantiFERON Gold and 16S rDNA on the bronchoalveolar lavage, confirming the diagnosis of EBTB. Subsequent RIPE treatment was initiated. Improvement of atelectasis on CXR was confirmed five days later when the patient was discharged from the pediatric intensive care unit to home. Patient was followed up in outpatient clinic and showed remarkable improvement and normalization of CXR. EBTB in infants is a rare yet high stakes diagnosis, with potential for significant morbidity if not identified early. While TB often presents with systemic signs, EBTB may masquerade as other airway disease or foreign body aspiration, particularly in infants, where cough may be mild or absent and auscultatory findings are subtle. Delayed recognition of EBTB correlates with fixed airway stenosis, prolonged hospitalization, and increased risk of bronchiectasis. In contrast, early anti-TB therapy, combined with steroids and, when indicated, airway intervention, can yield full resolution and avoid permanent damage. Interventional bronchoscopy, while rarely used in infants due to anatomical constraints, can be a prognosis altering procedure, offering substantial benefits to patients with relatively few downsides compared to an open surgical technique. This abstract is funded by: None