Smoking-Related Diffuse Cystic Lung Disease.

Exposure to cigarette smoke can lead to a variety of parenchymal lung diseases, including diffuse cystic lung diseases (DCLDs). Lymphangioleiomyomatosis (LAM) is the prototypical DCLD and has a characteristic appearance on high-resolution CT (HRCT). We present a series of four patients with DCLD on HRCT who were referred to our institution with a presumed diagnosis of LAM and who were found instead to have smoking-related injury of the small airways on histopathological analysis. We submit that cigarette smoke-induced small airway injury can present as DCLD on HRCT in a pattern that can mimic LAM. A detailed history of cigarette smoke exposure should be obtained in patients presenting with DCLD, and imaging features should not be used in isolation to establish a firm diagnosis of LAM.