Endobronchial Tuberculosis With Cavitation in Early Infancy: A Diagnostic Challenge

To the Editors, Endobronchial tuberculosis (EBTB) is a rare but important manifestation of Mycobacterium tuberculosis infection in infancy. It often mimics common pediatric respiratory illnesses such as bronchiolitis or pneumonia, leading to diagnostic delays. EBTB in infants under 6 months is extremely rare and requires high clinical suspicion and timely imaging.1 We present a 4-month-old female with cavitary pulmonary TB and endobronchial involvement—a rare and aggressive presentation emphasizing the role of early bronchoscopy. A 4-month-old female, born at term via cesarean (birth weight: 2850 g), developed persistent cough and wheezing at 2 months. She was hospitalized 3 times with presumed bronchiolitis or pneumonia and received antibiotics, bronchodilators, corticosteroids and intensive respiratory support. At 3.5 months, she was referred for unresolved respiratory distress. Examination showed bilateral wheezing and hypoxemia, requiring high-flow nasal cannula support. Inflammatory markers were mildly elevated; blood counts were unremarkable (white blood cell count: 6150/mm³; C-reactive protein: 18 mg/L; erythrocyte sedimentation rate: 4 mm/h; procalcitonin: 1.1 ng/mL). Tuberculin skin test was reactive (15 mm), and the interferon-gamma release assay was positive. Initial chest radiograph showed right lower lobe opacity (Fig. 1A). Chest computed tomography later revealed right lower lobe cavitary consolidation, mediastinal necrotic lymphadenopathy and bronchial narrowing—unusual in infants (Fig. 1B,C).FIGURE 1.: Radiologic and bronchoscopic findings in a 4-month-old infant with endobronchial tuberculosis. A: Chest radiograph showing right lower lobe opacity. B: Axial chest CT demonstrating cavitary consolidation and mediastinal necrotic lymphadenopathy. C: Coronal CT image revealing bronchial narrowing and necrotic lymph nodes. D: Bronchoscopic view of a nodular endobronchial lesion with caseating appearance.Flexible bronchoscopy identified a white nodular lesion compressing the right intermediate bronchus and narrowing the left main bronchus (Fig. 1D). Bronchoalveolar lavage and bronchial brushings were obtained. Acid-fast bacilli staining was negative, but gastric aspirates and bronchoscopic specimens were polymerase chain reaction-positive for M. tuberculosis. Based on these, standard 4-drug anti-TB therapy—isoniazid, rifampin, pyrazinamide and ethambutol (HRZE)—was initiated. Dissemination workup, including cerebrospinal fluid, cranial imaging, abdominal ultrasound and urinary polymerase chain reaction was unremarkable. Immunologic screening, including lymphocyte subsets, immunoglobulins, and oxidative burst test, was normal. HIV serology was negative. Further evaluation for Mendelian susceptibility to mycobacterial disease showed no abnormality. Initially, no household contact was identified. Later, it was revealed that the infant’s grandmother, who had been caring for her since she was 1 month old, had a chronic cough previously attributed to post-COVID symptoms. She was diagnosed with smear-positive pulmonary TB (acid-fast bacilli 2+), and culture confirmed M. tuberculosis, establishing her as the index case. Culture from the infant’s bronchoscopic specimen later confirmed M. tuberculosis, sensitive to isoniazid, rifampin and ethambutol. Histopathology showed granulomatous inflammation consistent with TB. She received 2 months of HRZE followed by 7 months of HR. Prednisolone was given for 4 weeks due to airway compression. Follow-up bronchoscopy revealed resolution of endobronchial lesions and negative polymerase chain reaction/culture, guiding therapy completion. Control chest radiograph also showed significant radiologic improvement. She demonstrated clinical and developmental improvement. EBTB in early infancy is frequently missed due to nonspecific signs and radiologic overlap with common infections. This case highlights bronchoscopy’s diagnostic value in atypical or refractory cases.2 Cavitation is rare at this age and often reflects diagnostic delay.3 Corticosteroids may help prevent complications like bronchial stenosis,4 and cavitary TB generally requires prolonged therapy.5 In endemic regions like Turkey, clinicians should maintain high suspicion when evaluating persistent respiratory symptoms. Early diagnosis, individualized therapy, and close follow-up are critical in managing severe infantile TB.