Question

A 72-year-old man is evaluated at the bedside following hospital admission for a 1-year history of progressive dyspnea, weight loss, low-grade fevers, fatigue, and myalgias. His past medical history is remarkable for atrial fibrillation, for which he takes amiodarone, hypercholesterolemia, and recurrent urinary tract infections, for which his urologist prescribed nitrofurantoin on a chronic, prophylactic basis. He denies any cigarette use, occupational exposure, history of murmurs or coronary artery disease, chest pain, wheezing, hemoptysis, syncope, abdominal pain, rashes, peripheral edema, diaphoresis, or vomiting. His physical exam reveals bilateral basilar crackles and digital clubbing, but is otherwise normal. A chest x-ray revealed peripheral reticular opacities at the lung bases and a generalized honeycombing pattern (refer to image).

Which of these is correct regarding additional diagnostic findings in this patient?

1. A high C-reactive protein, ESR, and titers of antinuclear antibodies are confirmatory.
2. Pulmonary function testing is expected to demonstrate an obstructive pattern.
3. Transbronchial biopsy is required for the diagnosis of this illness.
4. Bronchoalveolar lavage typically reveals neutrophilia and eosinophilia.
5. Computed tomography of the chest is an unnecessary diagnostic test.

Answer 1

A computed tomography (CT) of the chest is crucial in diagnosing interstitial lung disease and would not be considered an unnecessary test. Pulmonary function testing usually demonstrates a restrictive pattern, not obstructive. Bronchoalveolar lavage findings or systemic inflammation markers are not confirmatory for this condition.

Step-by-step explanation:

The individual in question exhibits symptoms and radiological findings highly suggestive of interstitial lung disease (ILD), possibly due to medication side effects, such as those that can be caused by amiodarone or nitrofurantoin. Of the possible diagnostic findings listed, answer choice 5 is incorrect as a computed tomography (CT) of the chest is an essential test in the workup of interstitial lung disease and would not be unnecessary. It provides crucial information beyond what a chest radiograph can offer, such as the extent of fibrosis and any other subtle patterns that aid in the diagnosis. Regarding answer choice 1, systemic inflammation markers like C-reactive protein, ESR, and autoantibodies (e.g., antinuclear antibodies) can be elevated in a variety of conditions and are not specific or confirmatory for ILD. Answer choice 2 is incorrect because ILD typically demonstrates a restrictive pattern on pulmonary function testing, not obstructive. While answer choice 3 mentions that a transbronchial biopsy is required for diagnosis, in some cases of ILD, a diagnosis can be made based on clinical, radiological, and pulmonary function test findings without the need for a biopsy. Lastly, answer choice 4 describes findings that may be seen in other conditions but are not specific to ILD; thus, bronchoalveolar lavage findings would not typically be diagnostic by themselves.