Thyroglossal Duct Cyst
Thyroglossal Duct Cyst
Thyroglossal duct cysts usually make themselves known early in life.
The thyroid gland in an embryo actually starts as a small group of cells at the very back of the base of the tongue. The base of the tongue is the posterior 1/3 of the tongue that you can see in the mirror if you stick your tongue way out. The furthest point backwards is where the thyroid begins. From here, in the earliest weeks of gestation the thyroid cells begin a journey downward along the midline of the neck until they arrive low in the neck just above the breast bone. These cells then grow into the butterfly shaped gland that we call the thyroid. The tubelike path that these cells took to get their final destination then closes up. If it doesn’t close in its entirety it may leave an open space that may fill up with fluid or a thick mucous like material. This fluid filled sac is called a thyroglossal duct cyst.
Thyroglossal duct cysts usually make themselves known early in life, either in childhood or young adulthood. Curiously, I recall one of my first months as a private surgeon in 1979 when I had three patients over the age of 50 that presented with thyroglossal duct cysts…a statistical anomaly to be sure. They are usually a round or oval soft mass found in the midline of the neck (or a little to the left of the midline) just above the Adams apple. Interestingly, there is a small horseshoe shaped bone that sort of floats in the neck at this level. This bone is called the Hyoid Bone. Various muscles from below and above attach to it, but the important thing about this bone is that the thyroglossal duct, the path those thyroid cells travel through, goes either just above, just below, or right through the hyoid bone. This is important to know when removing these cysts.
Most commonly they are about the size of a ping pong ball, but they can get much larger. If they get infected the skin may turn red, become tender, and sometimes these cysts will spontaneously rupture through the skin and the fluid and pus within will drip down the neck. Avoiding infection is one of the primary reasons to remove these cysts. Once infection occurs the abscess must be fully drained, irrigated, and antibiotics given. The infected thyroglossal duct cyst will eventually heal and then it can be removed, but the prior infection and inflammation makes the operation just a tad more difficult. For this reason, we don’t usually wait to take these out unless there is a good reason not to do so.
One other thing to consider is whether or not the thyroglossal duct cyst contains any thyroid tissue. This is uncommon, but not entirely rare. The reason the presence of thyroid tissue is important is two-fold. First, in a rare patient, it may be that the thyroid tissue in a thyroglossal duct cyst is the entire thyroid gland that did not make its normal descent to its correct anatomical location lower down in the neck. For this reason it is important to make sure the patient has a normal thyroid gland as well as the cyst. Second, thyroid cancer can exist in thyroid tissue within a thyroglossal duct cyst. If my memory serves me correctly, I’ve seen 3 cases of Papillary Cancer in a thyroglossal duct cyst. That’s not many after removing these for 35 years so you know it is a real rarity. When cancer is present, it needs to be treated just as thyroid cancer would be treated in the normal location. The prognosis is usually quite good.
The accepted procedure for removal of these cysts is called the Sistrunk procedure, named for Dr. Walter Ellis Sistrunk who described the procedure in 1920. The basis of this operation is to remove (all in one specimen) the cyst, the middle third of the hyoid bone, and follow the “tract” up to the base of tongue where it is ligated with a suture. See my photo below. Any less a procedure, and the risk of recurrence of the cyst can be quite high.
This is virtually always an outpatient procedure, there is little discomfort, the complication rate is extremely low, and the patient gets his or her suture removed about a week later and pretty much returns to normal activity, with the exception of not lifting heavy weights, playing rugby, and so on, for a few weeks. My most recent thyroglossal duct cyst patient taught me a new lesson about activity in the recovery period. When he came in for suture removal he looked and felt great, but there was obviously a fluid collection beneath his incision. This is unusual so I asked him what he had been doing. He replied that he had been singing Karaoke and playing “Air Guitar” with his nieces. This is probably not a good idea after a major operation next to the voice box and throat. Things need a little time to heal. He’s doing fine.
Below are some photos for you to help you understand thyroglossal duct cysts a little better. I hope this has been helpful.
6 days after surgery