Branchial Cleft Cysts

A branchial cleft cyst is a congenital cyst that appears on the side of the neck, usually just below the angle of the jaw. It results from incomplete closure of the branchial clefts, which form the face and neck during development in the womb. It is most often noticed in adolescence or young adulthood, when it swells after an upper respiratory tract infection.

What is a branchial cleft cyst?

In early development, the neck region contains branchial clefts, which resemble the gill slits of fish. Normally these clefts fuse and close. If part of one remains open, three different structures may form:

• Cyst: A closed, fluid-filled sac with no opening to the outside.
• Sinus: A blind-ended channel opening only onto the skin or only into the throat.
• Fistula: A channel open at both ends, onto the skin and into the throat.

Most cysts originate from the second branchial cleft and sit in the upper-middle part of the neck along the front edge of the large neck muscle (sternocleidomastoid). Less commonly, there are types seen in front of and around the ear, or in the lower part of the neck.

Symptoms

• A soft, mobile, mostly painless lump on one side of the neck
• Enlargement of the lump during a cold or throat infection, followed by some shrinkage
• Redness, tenderness and pain when it becomes inflamed
• If a sinus or fistula is present, a clear or sticky leak from a small opening in the skin of the neck
• With large cysts, a feeling of pressure during swallowing

Diagnosis

On examination, the position and consistency of the cyst give typical findings. Ultrasound shows the cystic structure of the lump and its contents. Magnetic resonance imaging (MRI) or computed tomography (CT) may be requested to see the depth of the cyst, whether it has a tract extending towards the throat, and its relationship with the large neck vessels. In adults, a fine-needle aspiration biopsy may be needed to distinguish a cystic mass on the side of the neck from other causes.

Treatment

Branchial cleft cysts do not disappear on their own. During an inflamed period, the inflammation is treated first and any collected pus is drained if necessary; however, these measures give only temporary relief. The permanent treatment is surgical removal of the cyst, and of its tract if present, in one piece. The operation is performed under general anaesthesia through an incision that follows the natural creases of the neck. If the tract extends as far as the throat, an approach through the mouth may also be needed to clear the remnant completely. Protecting the vessels and nerves along the course of the cyst is the most important stage of the operation.

What to expect after surgery

Mild pain and swelling in the neck are normal after surgery and subside within a few days. Most people go home after a short period of observation; because the incision is placed in a neck crease, the scar fades over time. When the cyst and tract are removed completely, recurrence is not expected; remnants left behind, on the other hand, can lead to renewed swelling. For this reason, it is important that the operation is planned for a quiet period free of inflammation.

When should you see a doctor?

• If there is a lump on the side of your neck that has not gone away for a few weeks
• If the lump repeatedly enlarges with infections
• If you have noticed a small leaking opening in the skin of the neck
• If the lump is hardening, growing quickly or making swallowing difficult