<unk>  most often does not cause symptoms. It is most frequently discovered as a soft mass or swelling in the neck of infants and children. However, when symptoms do occur they are most commonly due to compression of nearby structures such as the trachea and esophagus. This can lead to hoarse voice, stridor, difficulty breathing and/or difficulty swallowing. Pain is uncommon.
Ectopic thymus
Abscess of thymus
Cervical thymic cyst
Tracheal agenesis
Persistent thyroglossal duct
Salivary gland atresia
Ectopic salivary gland tissue
Salivary gland aplasia