09-09-2007, 09:30 AM
A 48-year-old man is evaluated for progressive exertional dyspnea and nonproductive cough. He is an ex-smoker (30-pack-years) and has gastroesophageal reflux, systemic hypertension, and hypothyroidism. His medications include a proton pump inhibitor, an ACE inhibitor, and thyroid hormone replacement.
On physical examination, sclerodactyly is noted and the P2 component of S2 is increased in intensity. Bibasilar, inspiratory crackles are audible. There is no peripheral edema. HRCT scan of the chest shows reticular lines most prominent in the periphery of the lower lobes, accompanied by patchy, ground-glass opacities. A patulous esophagus, enlarged pulmonary arteries, and mildly dilated right ventricle are noted. Pulmonary function testing shows a forced expiratory volume in 1 sec (FEV1) 84% of predicted, a forced vital capacity (FVC) 78% of predicted, and a diffusing lung capacity for carbon monoxide (DLCO) 39% of predicted. Pulse oximetry with the patient at rest and breathing room air is 94%; with brisk walking, the oximeter only intermittently obtains a signal. Rheumatoid factor is negative. Antinuclear antibody titer is 1:160 (one dilution above the upper limit of normal).
Which of the following is the most likely diagnosis?
A Idiopathic pulmonary fibrosis
B Systemic lupus erythematosus with pulmonary involvement
C Hypersensitivity pneumonitis
D Cranial nerve dysfunction
E Scleroderma with lung involvement
On physical examination, sclerodactyly is noted and the P2 component of S2 is increased in intensity. Bibasilar, inspiratory crackles are audible. There is no peripheral edema. HRCT scan of the chest shows reticular lines most prominent in the periphery of the lower lobes, accompanied by patchy, ground-glass opacities. A patulous esophagus, enlarged pulmonary arteries, and mildly dilated right ventricle are noted. Pulmonary function testing shows a forced expiratory volume in 1 sec (FEV1) 84% of predicted, a forced vital capacity (FVC) 78% of predicted, and a diffusing lung capacity for carbon monoxide (DLCO) 39% of predicted. Pulse oximetry with the patient at rest and breathing room air is 94%; with brisk walking, the oximeter only intermittently obtains a signal. Rheumatoid factor is negative. Antinuclear antibody titer is 1:160 (one dilution above the upper limit of normal).
Which of the following is the most likely diagnosis?
A Idiopathic pulmonary fibrosis
B Systemic lupus erythematosus with pulmonary involvement
C Hypersensitivity pneumonitis
D Cranial nerve dysfunction
E Scleroderma with lung involvement