Restrictive Lung Disease USMLE Step 1 Practice Question
A 52-year-old man with a 20-year history of cigarette smoking presents to the clinic with a 6-month history of progressive dyspnea on exertion and dry cough. He denies orthopnea, peripheral edema, or constitutional symptoms. Vital signs: BP 138/86 mmHg, HR 92 bpm, RR 22/min, SpO2 91% on room air. Physical examination reveals bibasilar end-inspiratory crackles. Chest radiograph shows bilateral lower lobe predominant reticular opacities with traction bronchiectasis. Pulmonary function tests demonstrate: FVC 65% predicted, FEV1 62% predicted, FEV1/FVC ratio 78%, total lung capacity 58% predicted, DLCO 52% predicted. High-resolution CT chest shows usual interstitial pneumonia (UIP) pattern. Which of the following is the most likely diagnosis?
Answer choices
- ANonspecific interstitial pneumonia (NSIP)
- BAsbestosis with obstructive physiology
- CIdiopathic pulmonary fibrosis (IPF)Correct answer
- DRespiratory bronchiolitis-interstitial lung disease (RB-ILD)
- EHypersensitivity pneumonitis
- FSarcoidosis with fibrotic phase
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.