May Be Caused by

 Common

Asbestosis

Atelectasis

Lipoma

Lymphoma

Mediastinal fibrosis

Mediastinitis

Pericardial cyst

Pericardial fat pad

Pleural fluid

Pleuropericardial adhesion

Pneumoconiosis

Postinfarction myocardial scar

Pulmonary edema

Pulmonary opacity

Teratoma

Thymic cyst

Thymolipoma

Thymoma

 Uncommon

Constrictive pericarditis

Funnel breast

Morgagni hernia

Pectus excavatum

Scimitar syndrome