The thyroid gland develops from the lower portion of the thyroglossal duct, which begins at the foramen caecum at the base of the tongue. If a portion of this duct remains patent it can form a cyst - a thyroglossal cyst.
The cysts are usually found between the isthmus of the thyroid gland and the hyoid cartilage, or just above the hyoid cartilage. They occur at any age but the majority are seen in patients between 15 and 30 years of age.
Presentation is usually, as a painless, smooth, cystic, midline swelling in the region of the hyoid bone. A thyroglossal cyst may become symptomatic if it becomes inflamed; resulting in pain and swelling.
On examination, the cyst rises as the patient swallows or protrudes their tongue because of its attachment to the tongue via the tract of thyroid descent. Often, it presents with infection requiring drainage prior to excision.
Last reviewed 01/2018