Main differential diagnosis of cystic lung diseases

Multiple cysts as main feature
 Lymphangioleiomyomatosis (sporadic or associated with tuberous sclerosis)∼100%[1]
 Pulmonary Langerhans cell histiocytosis>90%[2]
 Birt–Hogg–Dubé syndrome; familial pneumothorax>80%[3]
 Nonamyloid Ig deposition disease[4]
 Pulmonary amyloidosis[5]
 Primary and metastatic neoplasmsRare
 Infections, e.g. Pneumocystis jiroveciiRare
 Other, e.g. Niemann–Pick disease, neurofibromatosis, Ehlers–Danlos syndrome, Proteus syndrome, MALT lymphoma, Castleman disease, congenital pulmonary airway malformation, BPD, fire-eater's lung, hyper-IgE syndrome, Erdheim–Chester disease
Multiple cysts in interstitial lung disease
 Lymphocytic interstitial pneumonia>60%[6, 7]
 Hypersensitivity pneumonitis (subacute/chronic)13–39%[8, 9]
 Sjögren syndrome14–23%[10, 11]
 Desquamative interstitial pneumonia32%[12]
 Follicular bronchiolitis[13]
 Other, e.g. ankylosing spondylitis, lymphomatoid granulomatosis

Ig: immunoglobin; MALT: mucosa-associated lymphoid tissue; BPD: bronchopulmonary dysplasia. #: frequency of pulmonary cysts, when available; : in the early stage of pulmonary Langerhans cell histiocytosis, a purely nodular pattern can be seen.