A 65-year-old man is evaluated for progressively worsening dyspnea for the past year. His past medical history is significant for hypertension and acid reflux disease. Six months ago, he complained of a dry cough. At that visit, his omeprazole dose was increased from 20 mg daily to 20 mg twice daily, and his blood pressure medication was switched from lisinopril to amlodipine. These interventions did not help, however, and his symptoms continued to worsen. He is a lifelong nonsmoker and retired after working as a chemical engineer at an oil refinery for 35 years.
His temperature is 37.2 C (99 F), blood pressure is 120/80 mm Hg, pulse is 78/min, and respirations are 16/min. His pulse oximetry at rest is 94% on room air and decreases to 82% after walking for 3 minutes. He has finger clubbing. There is no jugular venous distension. Heart sounds are normal without murmurs. Lung auscultation shows diffuse, dry, mid-inspiratory crackles bilaterally. There is no swelling or tenderness of any joints, including the proximal interphalangeal and metacarpophalangeal joints of the hands.
Laboratory results are as follows:

High-resolution chest CT scan is performed; a representative image is shown below.

Which of the following is the most likely diagnosis in this patient?

Question

A 65-year-old man is evaluated for progressively worsening dyspnea for the past year.  His past medical history is significant for hypertension and acid reflux disease.  Six months ago, he complained of a dry cough.  At that visit, his omeprazole dose was increased from 20 mg daily to 20 mg twice daily, and his blood pressure medication was switched from lisinopril to amlodipine.  These interventions did not help, however, and his symptoms continued to worsen.  He is a lifelong nonsmoker and retired after working as a chemical engineer at an oil refinery for 35 years.
His temperature is 37.2 C (99 F), blood pressure is 120/80 mm Hg, pulse is 78/min, and respirations are 16/min.  His pulse oximetry at rest is 94% on room air and decreases to 82% after walking for 3 minutes.  He has finger clubbing.  There is no jugular venous distension.  Heart sounds are normal without murmurs.  Lung auscultation shows diffuse, dry, mid-inspiratory crackles bilaterally.  There is no swelling or tenderness of any joints, including the proximal interphalangeal and metacarpophalangeal joints of the hands.
Laboratory results are as follows:

High-resolution chest CT scan is performed; a representative image is shown below.

Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

This patient with progressive dyspnea, exertional hypoxemia, dry crackles, and digital clubbing has typical features of idiopathic pulmonary fibrosis (IPF). IPF generally presents in middle-age and older patients with dry cough, progressive dyspnea, and clubbing of fingers. High-resolution chest CT characteristically shows honeycombing, cystic changes, and traction bronchiectasis (especially at the bases and subpleural areas). Patients with classic high-resolution chest CT findings can be diagnosed with IPF without further testing. However, patients with inconclusive CT results may need a lung biopsy, which most commonly shows usual interstitial pneumonia. (Choice A) Patients with bronchiectasis characteristically complain of daily productive cough and thick sputum. Bronchial wall thickening and luminal dilation are seen on chest CT. chest CT (Choice B) Cryptogenic organizing pneumonia (COP) is characterized by cough, fever, dyspnea, malaise, and myalgias; presentation is similar to that of community-acquired pneumonia or flu-like illness. COP usually has an acute to subacute onset (<2 months), as opposed to the more insidious (usually >6 months) onset of IPF. COP is usually associated with fever, which may lead to recurrent doses of antibiotics before the diagnosis is clarified. Cryptogenic organizing pneumonia (Choice D) This patient has no history of rheumatoid arthritis, and no synovitis is noted on physical examination. Rheumatoid factor is often falsely positive in IPF and many other autoimmune and infectious diseases. (Choice E) CT imaging in sarcoidosis may reveal areas of fibrosis interspersed with areas of inflammation, but the absence of adenopathy or granulomas makes this diagnosis unlikely. Also, clubbing is frequently seen in IPF and in asbestosis, cystic fibrosis, bronchiectasis, and, occasionally, lung cancer. However, it is rarely seen in uncomplicated chronic obstructive pulmonary disease or sarcoidosis. sarcoidosis Educational objective: Idiopathic pulmonary fibrosis is characterized by progressive dyspnea, hypoxemia, and cough. Examination findings may include dry pulmonary crackles and digital clubbing. High-resolution CT scan may show honeycombing, cystic changes, and traction bronchiectasis. If CT is not diagnostic, lung biopsy may be needed. __________ References: Managing diagnostic procedures in idiopathic pulmonary fibrosis. (http://www.ncbi.nlm.nih.gov/pubmed/23728870) Highlights of HRCT imaging in IPF. (http://www.ncbi.nlm.nih.gov/pubmed/23734841) Clubbing: an update on diagnosis, differential diagnosis, pathophysiology, and clinical relevance. (http://www.ncbi.nlm.nih.gov/pubmed/15928621)

A 65-Year-Old Man Is Evaluated for Progressively Worsening Dyspnea for the Past