What a Bulla Isn’t
Other Terminology
lPneumatocoele: thin-walled (< 1mm), gas-filled space in the lung developing in association with acute pneumonia, usually staph, and usually transient
lCavity: gas-containing space in the lung having a wall > 1 mm thick
lCyst: thin-walled, air- or fluid-filled, with a wall that contains respiratory epithelium, cartilage, smooth muscle and glands
lBleb: intrapleural  cystic space, uncommon