Review Question - QID 100940

This clinical presentation is consistent with centriacinar emphysema, which is typically found in patients suffering from COPD as a result of long-term cigarette smoking.

Emphysema is one the common forms of COPD, the other being chronic bronchitis. Emphysema is characterized by the progressive destruction of the septa between alveoli, resulting in larger cavities being formed and a decrease in lung diffusion capacity. Emphysema is typically classified as either centriacinar or panacinar. The former involves primarily the upper lobes while the latter involves all lung fields, particularly the bases. The panacinar form commonly occurs with alpha-1-antitrypsin deficiency while the centriacinar form is common in chronic smokers. FEV1, FVC, and FEV1/FVC ratio are all typically decreased in patients with emphysema. Note: Centriacinar/panacinar are equivalent to centrilobular/panlobular.

Macnee et al. discuss some of the controversial theories surrounding the pathogenesis of COPD. These include a protease-antiprotease imbalance, oxidative stress increasing inflammation, and alveolar cell loss through apoptosis.

Horowitz et al. review alpha 1-antitrypsin deficiency, a genetic disorder that may result in premature pulmonary emphysema. They discuss advances in treatment, including human alpha 1-PI which has recently been purified and is available to prevent the development of disabling emphysema in affected individuals.

Illustration A depicts a chest radiograph of a patient with emphysema displaying a barrel chest and flattening of the diaphragm.
Illustration B shows a micrograph demonstrating emphysema. The left side of the image shows lung tissue with destruction of interalveolar septa. The right side of the image shows relatively normal lung tissue with preservation of interalveolar septa in comparison.

Incorrect Answers:
Answer 1: Panacinar emphysema is most commonly the result of alpha-1-antitrypsin deficiency rather than chronic smoking.
Answers 3 & 5: A pulmonary lung nodule raises suspicion for cancer, granuloma, fungal infection, or a number of other conditions. A calcified nodule is more likely to be the result of a granuloma resulting from a disease such as previous fungal infection, while a spiculated uncalcified nodule is suspicious for lung cancer or a metastasis.
Answer 4: The incidence of hypersensitivity pneumonitis in smokers is actually less than non-smokers. This pattern would not be expected in an emphysematous patient.