Pulmonary cyst

What it means

A round circumscribed space within a lung that is surrounded by an epithelial or fibrous wall of variable thickness. A cyst usually has a thin and regular wall (less than 2 mm) and contains air, although some may contain fluid.

The thin wall of cystic lesions differentiates them from cavitary processes, which have thicker and irregular walls and will not be discussed in this article. On chest radiographs, findings of a cyst are often subtle, consisting of lucencies and sometimes linear opacities. An air-fluid level can improve the visibility of a cyst and may suggest infection. For the investigation of cysts, CT is substantially more sensitive than chest radiography, showing a cyst as a ringlike lucency surrounded by a thin wall.

Rare diseases that can present with this4

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Lung cyst