Bronchogenic cyst
   Bronchogenic cyst is defined as a cavity which is the residual of congenital sexual growth. At birth, the cyst is located at one or both sides of the neck, that is, in front of the neck’s oblique muscle which is called Astrid colloid mastoid. This muscle extends from behind the ear to the collarbone. This type of cyst is smooth, painless and rarely gets infected.