Cystic lung disease
Thin walled <2 mm (>4 mm = cavity)
Well defined interface with normal lung
Epithelial or fibrous wall
Solitary cysts: incidentally discovered. Age-related or remnant of prior trauma or infection.
Multifocal/diffuse cysts: lymphoid interstitial pneumonia, lymphangioleiomyomatosis, Langerhan’s cell histiocytosis, (LIP/LAM/LCH)
Birt-Hogg-Dubé syndrome, tracheobronchial papillomatosis, or primary and metastatic cancers.
Multifocal/diffuse cysts + nodules: lymphoid interstitial pneumonia, Langerhans cell histiocytosis, light-chain deposition disease, and amyloidosis.
Multifocal/diffuse cysts + ground-glass opacities: lymphoid interstitial pneumonia, Pneumocystis jirovecii pneumonia and desquamative interstitial pneumonia.