Endobronchial Blood Clot as the Presenting Feature of Sputum-Negative Pulmonary Tuberculosis in a Young Adult: The Diagnostic Value of Bronchoscopic Tissue Sampling

Background: Pulmonary tuberculosis (TB) remains the foremost infectious cause of mortality in sub-Saharan Africa, yet endobronchial tuberculosis (EBTB)—defined by mycobacterial invasion of the tracheobronchial mucosa—continues to be diagnostically elusive. Sputum smear microscopy, the most widely available TB diagnostic test in resource-limited settings, is frequently negative in EBTB due to paucibacillary mucosal disease, creating a critical diagnostic gap that non-invasive testing cannot bridge. Haemoptysis from EBTB-related mucosal erosion can culminate in an organised endobronchial blood clot—a rare but potentially life-threatening complication that simultaneously obstructs the airway and harbours the very mycobacterial material needed for diagnosis. This dual clinical and diagnostic significance is underappreciated in practice. To the best of our knowledge, we present the first reported case of this presentation from Kenya, managed through a structured multimodal bronchoscopic protocol, with complete WHO-defined treatment success and objective bilateral radiological resolution at six months. Case Presentation: A 21-year-old BCG-naive male (70 kg) presented to a tertiary referral hospital in Nairobi, Kenya, with a seven-day history of moderate haemoptysis (~100 mL per episode), drenching night sweats, fever, and progressive weight loss. Clinical examination revealed haemodynamic stability (HR 87 bpm, BP 120/80 mmHg, SpO₂ 99% on room air) with absent right lung breath sounds, directly predictive of the complete right main bronchial obstruction confirmed bronchoscopically. Chest radiograph demonstrated bilateral pulmonary infiltrates with left-predominant consolidation. Contrast-enhanced CT revealed bilateral ground-glass opacities, right lower lobe consolidation, and a centrally cavitating left upper lobe nodule (12.2 mm) with adjacent calcific foci. Laboratory investigations demonstrated moderate anaemia (Hb 9.0 g/dL), mild thrombocytopenia (platelets 120 × 10⁹/L, a recognised manifestation of active TB), elevated CRP (55 mg/L), normal coagulation studies (APTT and INR), normal liver function tests, and normal baseline visual acuity (Snellen 6/6 bilaterally; Ishihara colour vision normal). HIV was confirmed negative by both ELISA and PCR. A BioFire FilmArray Respiratory Panel was comprehensively negative for all viral and atypical bacterial respiratory pathogens, systematically excluding alternative infectious aetiologies. Sputum AFB smear microscopy was negative. Flexible bronchoscopy under general anaesthesia