A thyroglossal cyst is an abnormal mass that appears on the front of the neck, usually about halfway between the chin and the top of the chest. It results from a congenital defect of the thyroglossal duct, the embryonic precursor of the thyroid gland. A cyst may be obvious shortly after birth or take several years to grow large enough to be noticeable. Small asymptomatic masses do not generally require immediate treatment, but a large, growing, or infected thyroglossal cyst may need to be surgically removed to relieve symptoms and prevent health complications.
During early embryonic development, the thyroid gland begins to form near the base of the tongue. A temporary canal called the thyroglossal duct helps to move the thyroid downward in the neck to its permanent location. In normal development, the duct involutes, or folds in on itself, after the thyroid descends. A thyroglossal cyst develops if the duct does not involute properly and the remnants of thyroid tissue become trapped in the neck.
A very small thyroglossal cyst may never cause noticeable symptoms or health problems. Larger cysts, which can be about half an inch (about 1.25 centimeters) in diameter or bigger, often result in swallowing or breathing difficulties. If a cyst becomes infected, an individual can experience a number of uncomfortable symptoms. The mass can become tender, red, and swollen with infection, and pus may drain down the throat or through a break in inflamed skin. It is important to visit a pediatrician or the emergency room as soon as possible when a child shows signs of an infected thyroglossal cyst.
A doctor can usually diagnose a thyroglossal cyst with a careful physical examination. He or she might conduct an ultrasound or a computerized tomography scan to study the thyroid gland and confirm the presence of thyroglossal duct tissue in the throat. Blood and tissue samples are taken and analyzed in a clinical lab to make sure that the cyst is not cancerous or the result of a more serious medical condition. After making a diagnosis, treatment options can be considered.
Infected cysts are generally treated with oral antibiotics. If the skin over a cyst is broken, a patient may need to apply topical antibiotics as well to promote faster healing. Surgery is usually necessary in the case of large cysts that cause breathing problems or become frequently infected. A surgical specialist can make a small incision in the neck, drain excess pus and fluid, and excise the entire mass. The procedure has a high success rate and most patients do not have long-term or recurring thyroid problems.