There is an overlap in the use and description of the terms paratracheal air cyst and a tracheal diverticulum in the literature that they often seem to be synonyms for the same entity .
Tracheal diverticula are typically asymptomatic but can occasionally present with chronic cough, stridor, dyspnea, or recurrent infection .
Tracheal diverticula can be :
- prolonged increase intraluminal pressure, e.g. chronic cough, COPD
- iatrogenic, e.g. post-surgical
It projects posteriorly where the cartilage rings are deficient and usually lies to the right where there is no esophagus supporting the paratracheal tissue . The vast majority (97%) are located to the right posterolateral aspect of the trachea, about the level of the thoracic inlet . A direct connection with the trachea may not always be shown on CT .
- chronic obstructive pulmonary disease (COPD): for acquired type
- tracheobronchomegaly: when multiple tracheal diverticula are present
Treatment and prognosis
Although usually asymptomatic, it may accumulate respiratory secretions that become infected (and potentially abscess-forming) and lead to coughing or tracheobronchitis.