Diffuse Parenchymal Lung Diseases With a Known Cause

Question · easy

A 48-year-old asymptomatic heavy smoker is found to have patchy ground-glass opacities and fine centrilobular nodules on HRCT obtained for another reason. Bronchoalveolar lavage shows increased pigmented ('smoker's') macrophages confined to the respiratory bronchioles, consistent with respiratory bronchiolitis–associated interstitial lung disease (RB-ILD). Which of the following is the most appropriate primary management?

Antifibrotic therapy with nintedanib Cyclophosphamide induction therapy Chronic oral prednisone at 1 mg/kg/day Smoking cessation as the primary therapy, with clinical follow-up

Question · easy

A 55-year-old pigeon breeder presents with months of progressive dyspnea, cough, and weight loss. HRCT shows diffuse centrilobular micronodules and ground-glass opacities with septal thickening and early traction bronchiectasis, consistent with chronic fibrotic bird fancier's lung (hypersensitivity pneumonitis). Which of the following is the cornerstone of management?

Complete and permanent removal from the avian antigen exposure Prophylactic broad-spectrum antibiotics Long-term prednisone monotherapy as definitive treatment Immediate surgical lung biopsy before any intervention

Question · medium

A 68-year-old woman completed thoracic radiation for non–small cell lung cancer 8 weeks ago and now reports progressive cough, dyspnea, low-grade fever, and fatigue. Oxygen saturation is 88% on room air. HRCT shows ground-glass opacification and consolidation with a sharply demarcated, nonanatomic boundary that conforms exactly to the prior radiation port; infectious workup is negative. Which of the following is the best next step in management?

Empiric re-irradiation of the affected field Observation alone with repeat imaging in 3 months Bronchoscopic lung biopsy to confirm tumor recurrence before treating Systemic glucocorticoids (e.g., prednisone or methylprednisolone)

Question · medium

Across connective tissue diseases as a group, NSIP is the most common ILD pattern. Which of the following CTDs is the recognized exception, in which UIP predominates and carries a survival disadvantage comparable to idiopathic pulmonary fibrosis?

Polymyositis/dermatomyositis Systemic sclerosis Sjögren syndrome Rheumatoid arthritis

Question · hard

A 34-year-old heavy smoker has biopsy-confirmed pulmonary Langerhans cell histiocytosis (CD1a-positive Langerhans cells) with upper- and mid-lung cysts and nodules. Despite 6 months of complete smoking cessation and a glucocorticoid trial, his DLCO continues to decline and cystic disease progresses. According to the 2025 adult Langerhans cell histiocytosis guideline, which of the following is the most appropriate next step?

Escalation to high-dose inhaled corticosteroids Somatic MAPK-pathway mutation testing (including BRAF V600E) and consideration of systemic therapy with cladribine or targeted BRAF/MEK inhibition Empiric anti-tuberculous therapy for cavitary lung disease Reassurance with repeat pulmonary function testing in 12 months