Imaging of Cystic Lung Disease

Diffuse cystic lung disease refers to multiple rounded lucencies or low-attenuating areas with well-defined interfaces with normal lung. Parenchymal lucencies, such as cavitary disease, may mimic cystic lung disease. Cystic lung disease generally has a nonspecific presentation. Pulmonary cysts may present in isolation or with ancillary imaging features, such as ground-glass opacities or nodules. Clinical features, such as connective tissue disease, can narrow the differential diagnosis. In cases with indeterminate imaging and clinical features, open lung biopsy should be considered. Ultrarare cystic lung diseases, such as light chain deposition disease, can mimic more common diseases.