Arises from parenchymal cells which have been isolated during budding and branching to form a mass of non - functioning pulmonary tissue. Central cysts are of early embryonic origin. They are solitary and usually asymptomatic until infection ocurs.
Located near the pulmonary hilum or in the mediastinum (near the esophagus).
The lesions appear as solid masses or they are air filled (fluid level) when they communicate with the airways.
Rapid enlargement of a tension cyst may produce sudden respiratory distress.
Malignant transformation has been described.
If the lesion becomes infected symptoms like fever, hemoptysis, cough with purulent secretions occur.
X-ray, High – resolution CT scan.
Indication for operation:
The asymptomatic cyst is also a clear indication for excision.
Chest tubes may be removed if the lung is fully expanded and drainage volumes decrease below 20 to 50cc during a 24 hour period.