C40-07 From Cough to Cobblestones: Unmasking Endobronchial Sarcoidosis

Abstract Introduction Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology, characterised by the presence of non-caseating granulomas in affected tissues. Although extensive endobronchial involvement in sarcoidosis is described, it is a relatively rare manifestation of the condition. Case Presentation A 36-year-old man presented to the Emergency Department with a 3-month history of cough productive of green sputum, haemoptysis, dyspnoea, wheeze, fever and fatigue. He denied pleuritic chest pain, calf tenderness, recent surgery, travel, or known tuberculosis (TB) exposure. He reported a 15kg unintentional weight loss. Past medical history was significant for hypertension, managed with amlodipine. Family history was non-contributory. He was a lifelong non-smoker. He had no significant environmental exposures kept no pets, and worked in an office. He immigrated to Ireland from Nigeria three years earlier. Physical examination revealed left basal crepitations but was otherwise unremarkable. Initial laboratory testing showed elevated CRP (52 mg/L) and D-dimer (1.1 µg/mL). Full blood count, renal, liver and bone profile, including serum calcium, were normal. Respiratory viral PCR and urinary antigen testing were negative. Chest radiography revealed diffuse reticulonodular infiltrates bilaterally. CT pulmonary angiogram demonstrated marked bilateral perifissural nodularity, dense patchy perihilar consolidation, and bihilar and mediastinal lymphadenopathy. While characteristic of stage II pulmonary sarcoidosis, TB remained an important differential. Sputum AFB staining, TB GeneXpert testing, mycobacterial and bacterial culture were negative. QuantiFERON-TB Gold testing was negative while the serum ACE was elevated at 373 IU/L. Bronchoscopy revealed markedly abnormal erythematous airways with a nodular, cobblestone appearance (Figure 1). Bronchial washing TB GeneXpert testing, mycobacterial and bacterial cultures were negative. Endobronchial biopsies demonstrated well-formed non-caseating granulomas, favouring a diagnosis of sarcoidosis. He was treated empirically with antibiotics and discharged with outpatient follow-up arranged. On review, he reported partial improvement in fatigue and stabilisation of his weight. However, he continued to experience significant dyspnoea and wheeze. Pulmonary function testing (PFT) demonstrated a moderate restrictive ventilatory defect (forced vital capacity (FVC) 57% of predicted, forced expiratory volume in 1 second (FEV₁) 55% of predicted, FEV₁/FVC ratio 0.79). Diffusion of the lung for carbon monoxide (DLCO) was preserved (80% of predicted). He was commenced on oral prednisolone, with significant improvement in symptoms and PFTs. Discussion This case highlights the diagnostic complexity in patients from TB-endemic areas presenting with cough, haemoptysis, and constitutional symptoms. A notable feature in this case was endobronchial involvement with tissue biopsy and exclusion of other potential aetiologies essential for accurate diagnosis. This abstract is funded by: None