The pathogenesis of<unk>  is not certain, but it is thought to be due to an inflammatory reaction and fibrosis in the superficial layer of the pleura. As the fibrous tissue matures, it contracts, causing pleura to fold into the lung, which in turn causes<unk> .<unk>  is almost always asymptomatic and is detected on chest radiographs obtained for other reasons. A history of asbestos exposure is frequently (in 70% of cases) present. Asbestos-related<unk>  is also known as asbestos pseudotumor or Blesovsky syndrome. Conditions such as congestive heart failure], pulmonary infarction], Dressler syndrome, parapneumonic effusion, tuberculous effusion, and nonspecific pleurisy can precede<unk>  formation. Lung cancer] is the main differential diagnosis. After diagnosis, a follow-up CT should be obtained to exclude lung cancer.
The typical chest radiographic appearance is of a rounded peripheral "mass" with or without lung distortion.
Pleural thickening is usually seen.
The CT features are:
A round or oval mass that abuts the pleura
Has sharp lung borders
Has a fuzzy border which projects to the hila (Origin of Comet tail sign)
a "comet tail" of bronchovascular structures going into the mass (Comet tail sign).
Thickening of the adjacent pleura.
A round or oval mass that abuts the pleura
Has sharp lung borders
Has a fuzzy border which projects to the hila (Origin of Comet tail sign)
a "comet tail" of bronchovascular structures going into the mass (Comet tail sign).
Thickening of the adjacent pleura.
Volume loss is often, but not invariably, apparent.
Round atelectasis
Pleural friction rub
White out of the hemithorax
Trapped lung
Round pneumonia
Subcutaneous emphysema
Tracheal deviation
Diaphragmatic eventration