Cervical sinus
During human embryogenesis, the mandibular arch and hyoid arch grow more rapidly than those behind them, with the result that the latter become, to a certain extent, telescoped within the former, and a deep depression, the cervical sinus, is formed on either side of the neck.
This sinus is bounded in front by the hyoid arch, and behind by the thoracic wall; it is ultimately obliterated by the fusion of its walls.
Sometimes, it can remain anterior to the sternocleidomastoid muscle. It can communicate with the skin or with the pharynx. It is prone to infection.
