SERPINA1 and Birt-Hogg-Dube syndrome: Pulmonary cysts in BHD are elliptical and lentiform-shaped, often subpleural, and distributed predominantly in the lower lung zones [6,10]. Emphysema due to alpha-1 antitrypsin deficiency and infectious causes like Pneumocystis carinii can also mimic the appearance of cystic lung diseases, and the medical team should be mindful of them too.