May Be Caused by

 Common

Bronchogenic cyst

Duplication cyst

Neurenteric cyst

Pericardial cyst

Tracheal cyst

 Uncommon

Acquired thymic cyst

Anterior meningocele

Congenital thymic cyst

Cystic thymoma

Granulomatous lymphadenitis

Hydatid cyst

Idiopathic mediastinal cyst

Intrathoracic goiter

Lateral meningocele

Lymphangioma

Lymphocele

Lymphoma

Mature teratoma

Myelomeningocele

Neurogenic tumor

Pancreatic pseudocyst