Cystic Lung Disease in Birt-Hogg-Dubé Syndrome

BackgroundTo describe the clinical, radiologic, and histopathologic aspects of cystic lung disease occurring in patients with Birt-Hogg-Dubé (BHD) syndrome, a rare, inheritable, multisystem disorder.MethodsWe retrospectively reviewed five patients with BHD syndrome evaluated at the Mayo Clinic Rochester from 1998 through 2005.ResultsMean age (± SD) at the time of pulmonary evaluation was 56.4 ± 4.8 years; four patients were men. Three patients had not received a diagnosis of BHD syndrome at the time of initial CT of the chest. Three patients had a smoking history, and two were nonsmokers. Two patients had a history of recurrent pneumothoraces. Pulmonary function tests available in four patients revealed normal results in one patient and mild airflow obstruction or nonspecific pattern of abnormalities in three patients. CT of the chest revealed cystic lung disease in all five patients; cysts were round to oval in shape, ranged widely in size, and were randomly distributed throughout the lungs, except for a predilection to involve the lung bases more extensively. Three patients with a smoking history had more severe cystic changes compared to nonsmokers and included both patients with recurrent pneumothoraces. Surgical lung biopsy available in one patient revealed emphysema-like changes. Follow-up CT scans available in four patients revealed relative stability over a median interval of 20 months (range, 3 to 66 months).ConclusionWe conclude that cystic lung disease in BHD syndrome varies widely in severity, mimics pulmonary lymphangioleiomyomatosis, and may be worsened by smoking.