[Computed tomography of cystic lung diseases]

A cystic lesion in the lung is defined as a well-demarcated epithel-lined cavity, that can be mostly filled with air, water, as well as solid material content. This definition includes a wide variety of diseases such as bronchogenic cyst, abscess formation, lymphangioleiomyomatosis, Langerhans cell histiocytosis, emphysema, bronchiectasis, and pneumatoceles. Despite the difficulties in differential diagnosis, there are some diagnostic criteria for CT-scanning helping the radiologist to differentiate between these cystic entities. Moreover, clinical informations are extremely important. The most important clinical parameters include age, sex, clinical history and symptoms. Thus, a better understanding of classic CT appearance of cystic lung disease will allow more definitive diagnosis and could, in some cases, avoid biopsy.