Thyroglossal duct cyst

A thyroglossal duct cyst develops when the duct along which the thyroid normally migrates in the womb, from the base of the tongue to the area where the thyroid sits, fails to close at some point along its course. This duct passes through the hyoid bone. It appears as a swelling exactly in the midline of the neck. Rarely, thyroid cancer can develop within it. Patients present with a painless mass in the midline of the neck. Following an upper respiratory tract infection, the cyst becomes infected and begins to grow. The mass can be seen to move when the tongue is stuck out. It can easily be diagnosed with MRI and ultrasound (USG). In highly suspicious cases, the swelling can be entered under ultrasound guidance and a biopsy taken. The cyst and its duct are removed surgically together with the hyoid bone. Failure to remove the hyoid bone leads to recurrence.