What is a branchial cleft cyst?

A branchial cleft cyst is a type of birth defect in which a lump develops on one or both sides of your child’s neck or below the collarbone. This type of birth defect is also known as a branchial cleft remnant.

This birth defect occurs during embryonic development when tissues in the neck and collarbone, or branchial cleft, don’t develop normally. It may appear as an opening on one or both sides of your child’s neck. Fluid draining from these openings may form in a pocket, or a cyst. This can become infected or seep out of an opening in your child’s skin.

This is a congenital birth defect that occurs early in embryonic development. Major neck structures form during the fifth week of fetal development. During this time, five bands of tissue called pharyngeal arches form. These important structures contain tissues that’ll later become:

  • cartilage
  • bone
  • blood vessels
  • muscles

Several defects in the neck can occur when these arches fail to develop properly.

In branchial cleft cysts, the tissues that form the throat and neck don’t develop normally, creating open spaces called cleft sinuses on one or both sides of your child’s neck. A cyst may develop from fluids that are drained by these sinuses. In some cases, the cyst or sinus may become infected.

There are several types of branchial cleft abnormalities.

  • First branchial cleft anomalies. These are cysts around the earlobe or under the jaw, with an opening below the jaw and above the larynx, or voice box. This type is rare.
  • Second branchial cleft sinuses. These are sinus tracts that open on the lower part of the neck. They may go as far as the tonsil area. You may be able to see skin tags or feel the tract opening as a band in your child’s neck. These cysts generally appear after age 10. This is the most common type of branchial cleft abnormality.
  • Third branchial cleft sinuses. These are near the thyroid gland in the front part of the muscle that attaches to your child’s collarbone. This type is very rare.
  • Fourth branchial cleft sinuses. These are below the neck. This type is also quite rare.

In most cases, a branchial cleft cyst isn’t dangerous. However, the cyst can drain and cause skin irritation. Cysts can also become infected, causing difficulty with swallowing and breathing. Cancerous tumors may develop at the site of a branchial cleft in adults, but this is very rare.

A branchial cleft cyst usually doesn’t cause pain unless there’s infection. The signs of a branchial cleft cyst include:

  • a dimple, lump, or skin tag on your child’s neck, upper shoulder, or slightly below their collarbone
  • fluid draining from your child’s neck
  • swelling or tenderness in your child’s neck, which usually occurs with an upper respiratory infection

If your child has signs of a branchial cleft cyst, take them to their doctor promptly.

Most of the time, a doctor will diagnose this condition during a physical exam. Diagnostic imaging tests to determine the exact location may include an MRI scan, a CT scan, or an ultrasound.

Additional diagnostic testing may include a microscopic examination of the fluid from a fine needle aspiration. In this procedure, your child’s doctor inserts a small needle into the cyst to remove fluid for analysis. They may also examine tissue from a biopsy.

Your child’s doctor will likely prescribe antibiotics if your child has signs of infection. It may be necessary to drain fluid from the cyst to ease swelling. To prevent future infections, doctors usually recommend surgery to remove the cyst.

A surgeon will usually perform the surgery on an outpatient basis. This means your child can go home the same day. Your child will also be under general anesthesia. They’ll fall asleep and won’t feel any pain during the procedure.

Your child will be unable to take a bath or play actively for a few days following surgery. Bandages can come off within five to seven days after surgery.

Surgery usually results in a good outcome. However, cysts can recur, especially if surgery happened during an active infection. Follow the instructions from your child’s doctor on the best way to recover from the surgery. This will increase the chances for a quick recovery.