Neck Cysts and Fistulas: Causes, Symptoms & Treatment

What Are Neck Cysts and Fistulas?

Neck cysts are fluid-filled sacs that develop from embryological remnants present from birth. A fistula is an abnormal tract connecting the cyst to the skin surface. These congenital conditions typically appear as soft lumps on the neck and may require surgical removal if they become infected or cause symptoms.

Neck cysts and fistulas are congenital anomalies, meaning they are present from birth even though they may not be discovered until later in life. During normal fetal development, certain embryological structures should disappear before birth. When these structures persist, they can form cysts (fluid-filled sacs) or fistulas (abnormal tunnels or tracts).

The term "cyst" refers to a closed, fluid-filled cavity that forms under the skin, appearing as a soft lump or bump. The fluid inside is typically mucoid or serous in nature. A "fistula," on the other hand, is an abnormal passage or tract that may connect the cyst to the skin surface or to internal structures. When a fistula is present, fluid may drain through a small opening in the skin, particularly during infections.

These conditions are relatively common among congenital neck anomalies. Many people live their entire lives without knowing they have a small cyst, as it may never cause symptoms. However, when cysts become infected, enlarge, or cause cosmetic concerns, medical attention becomes necessary. Understanding the different types and their characteristics helps in recognizing when to seek care.

Branchial Cysts and Fistulas

Branchial cysts, also known as lateral cervical cysts, arise from remnants of the branchial arches and clefts that form during early embryonic development. These structures normally develop into various parts of the head and neck, including parts of the ear, jaw, and throat. When they fail to completely regress, cysts or fistulas can form.

Branchial anomalies account for approximately 20% of all congenital neck masses. They most commonly appear on the side of the neck, typically along the anterior border of the sternocleidomastoid muscle. Second branchial arch anomalies are the most common type, representing about 95% of all branchial anomalies. These typically present as a painless, fluctuant mass in the lateral neck that may enlarge during upper respiratory infections.

Thyroglossal Duct Cysts

Thyroglossal duct cysts develop from remnants of the thyroglossal duct, the embryological structure through which the thyroid gland descends from the base of the tongue to its final position in the neck. This duct normally obliterates (closes and disappears) by the tenth week of gestation. When it persists, cysts can form anywhere along its path from the tongue base to the thyroid gland.

Thyroglossal duct cysts are the most common congenital midline neck mass, representing approximately 70% of such anomalies. They typically present as a midline or slightly off-midline neck mass that moves upward with swallowing or tongue protrusion. This characteristic movement helps distinguish them from other neck masses and is an important diagnostic feature during physical examination.

What Are the Symptoms of Neck Cysts and Fistulas?

The most common symptom is a soft, movable lump on the neck. When infected, the area may become painful, swollen, red, and may drain foul-smelling fluid. Many cysts remain asymptomatic for years before being discovered, often during routine examination or when infection occurs.

The presentation of neck cysts and fistulas varies considerably depending on whether the cyst is infected and its specific location. Many individuals have cysts that remain completely asymptomatic for years or even decades. The cyst may be discovered incidentally during a routine physical examination, or it may become apparent only when it enlarges or becomes infected.

Understanding the range of possible symptoms helps in recognizing when a neck lump might be a cyst or fistula rather than another condition such as swollen lymph nodes, which are a more common cause of neck swelling.

• Soft, painless lump: A movable mass under the skin, often discovered incidentally
• Swelling or enlargement: The area around the lump may become more prominent
• Tenderness or pain: Usually indicates infection or inflammation
• Skin color changes: Redness on lighter skin; may appear purple or unchanged on darker skin
• Fluid drainage: Discharge from a small opening, especially with fistulas
• Foul-smelling discharge: Often indicates bacterial infection requiring treatment

Symptoms of Uninfected Cysts

When not infected, neck cysts typically present as painless, soft lumps that may have been present for months or years without causing concern. The cyst feels smooth and round, moves easily under the skin, and doesn't cause tenderness when touched. The overlying skin appears normal without any color changes.

Thyroglossal duct cysts have a distinctive characteristic: they move upward when the person swallows or sticks out their tongue. This occurs because the cyst is attached to the hyoid bone through the thyroglossal tract. This movement pattern is a helpful diagnostic feature that healthcare providers look for during examination.

Branchial cysts typically feel fluctuant, meaning they give a sense of fluid movement when pressed. They may slowly enlarge over time, particularly during upper respiratory infections when the lymphoid tissue in the area becomes more active.

Symptoms of Infected Cysts

Infection transforms an asymptomatic cyst into a painful, concerning mass. The first sign is usually rapid enlargement over hours to days, accompanied by increasing tenderness. The overlying skin becomes warm to the touch and may appear red on lighter skin tones. On darker skin, the color change may be less apparent, appearing more purple or showing no visible change, though warmth can still be felt.

As infection progresses, the cyst may develop into an abscess—a collection of pus that requires drainage. Fever may accompany the local symptoms, indicating a more significant infection. In severe cases, the infection can spread to surrounding tissues, causing cellulitis (skin infection) or even deeper infections that require hospitalization.

If a fistula is present, the infection may drain spontaneously through the skin opening. While this may provide some relief from pressure, it also indicates that surgical treatment will likely be necessary to prevent recurrence.

When Should You See a Doctor for a Neck Lump?

See a doctor if you notice a new or changing lump on your neck, especially if it's painful, growing, or draining fluid. Seek immediate care if you have fever with neck swelling or difficulty breathing or swallowing. Most neck lumps have benign causes, but evaluation is important to determine the cause and treatment.

Not every neck lump requires urgent medical attention. However, certain characteristics warrant evaluation by a healthcare provider. Understanding when to seek care helps ensure appropriate treatment while avoiding unnecessary worry about benign conditions.

Contact your healthcare provider or visit a clinic if you experience any of the following:

• A new lump or bump on your neck that persists for more than two weeks
• A known lump that suddenly increases in size
• Pain, tenderness, or warmth at the site of a lump
• Redness or skin color changes over a lump
• Fluid draining from an opening in the skin
• Foul-smelling discharge from the neck
• Recurrent infections in the same area

Your primary care provider can perform an initial evaluation and determine whether referral to an ear, nose, and throat (ENT) specialist is appropriate. ENT specialists, also known as otolaryngologists, have specific expertise in diagnosing and treating neck cysts and fistulas.

How Are Neck Cysts and Fistulas Diagnosed?

Diagnosis begins with physical examination, where the doctor inspects and feels the neck mass. Imaging studies such as ultrasound, CT scan, or MRI help confirm the diagnosis and plan treatment. The characteristic location and behavior of the mass often provides important diagnostic clues.

The diagnostic process for neck cysts and fistulas typically involves a combination of clinical examination and imaging studies. A thorough evaluation helps distinguish cysts from other neck masses and provides essential information for surgical planning if removal is needed.

Physical Examination

The initial evaluation involves a detailed history and physical examination. Your doctor will ask about when you first noticed the lump, whether it has changed in size, and whether you've experienced pain, infection, or drainage. Family history may also be relevant, as some congenital anomalies can have genetic components.

During the physical examination, the doctor will carefully inspect and palpate (feel) the neck mass, noting its size, location, consistency, and mobility. For suspected thyroglossal duct cysts, the doctor will ask you to swallow and protrude your tongue while observing whether the mass moves upward—a hallmark characteristic of this type of cyst.

The doctor will also perform a general head and neck examination, including looking at the throat and ears, and may examine the tongue base if a thyroglossal duct cyst is suspected. This comprehensive evaluation helps rule out other conditions and provides important information for diagnosis.

Imaging Studies

Imaging plays a crucial role in confirming the diagnosis and planning treatment. Several modalities may be used:

Ultrasound is often the first imaging study performed. It's non-invasive, doesn't involve radiation, and can distinguish between solid and cystic (fluid-filled) masses. Ultrasound can show the size, location, and internal characteristics of the cyst, and can identify the relationship to surrounding structures.

CT (computed tomography) scanning provides more detailed images and is particularly useful for surgical planning. CT can show the full extent of a fistula tract and its relationship to important structures like blood vessels and the thyroid gland. It's especially valuable when infection or abscess is suspected.

MRI (magnetic resonance imaging) offers excellent soft tissue detail without radiation exposure. It's particularly useful for evaluating thyroglossal duct cysts and their relationship to the tongue base. MRI is often preferred in children due to the lack of radiation.

Additional Tests

In some cases, additional tests may be needed. Fine needle aspiration (FNA), where a small needle is used to extract fluid from the cyst, can help confirm the diagnosis and rule out other conditions. The fluid can be analyzed for cell type and, if infection is present, cultured to identify bacteria.

For thyroglossal duct cysts, thyroid function tests may be performed to ensure the thyroid gland is functioning normally. In rare cases, the cyst may contain the only functioning thyroid tissue, which would change the treatment approach.

How Are Neck Cysts and Fistulas Treated?

Surgical removal is the definitive treatment for symptomatic neck cysts and fistulas. For infected cysts, antibiotics are given first to control infection before surgery. The Sistrunk procedure is the standard operation for thyroglossal duct cysts, while branchial cyst excision requires complete removal of the cyst and any associated fistula tract.

Treatment of neck cysts and fistulas depends on whether symptoms are present and whether the cyst is infected. While small, asymptomatic cysts may be monitored over time, surgical removal is generally recommended once symptoms develop or infection occurs. Understanding the treatment process helps patients prepare for what to expect.

Conservative Management

Not all neck cysts require immediate surgery. Small, asymptomatic cysts may be monitored with periodic clinical examination and imaging. However, once a cyst becomes infected, the likelihood of recurrent infections increases significantly, making surgical removal the preferred approach.

If a cyst becomes infected, initial treatment typically involves antibiotics to control the infection. Your doctor will prescribe appropriate antibiotics based on the suspected bacteria. Warm compresses may help provide comfort and promote drainage if a fistula is present.

Pain management during infection typically involves over-the-counter medications such as acetaminophen (paracetamol). It's important to avoid non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen for about a week before planned surgery, as they can increase bleeding risk.

Surgical Treatment

Surgical excision is the definitive treatment for neck cysts and fistulas. The goal is complete removal of the cyst, any associated fistula tract, and surrounding abnormal tissue to prevent recurrence. The specific surgical approach depends on the type and location of the anomaly.

Surgery is performed under general anesthesia. The surgeon makes an incision along natural skin creases when possible to minimize visible scarring. For branchial cysts, the incision is typically made on the side of the neck overlying the mass. For thyroglossal duct cysts, a horizontal incision is made in the midline neck.

The Sistrunk procedure is the standard surgical technique for thyroglossal duct cysts. This procedure involves removing the cyst along with the central portion of the hyoid bone and a core of tissue extending to the tongue base. This comprehensive approach is necessary because the thyroglossal duct passes through or around the hyoid bone, and incomplete removal leads to high recurrence rates.

For branchial cyst excision, the surgeon must trace and remove the entire fistula tract if present. This may require following the tract deep into the neck, sometimes requiring multiple incisions for complete access. The proximity to important structures such as nerves and blood vessels requires careful surgical technique.

Recovery After Surgery

Most patients stay in the hospital for one to three days after surgery, though some may be discharged the same day depending on the extent of the procedure and individual circumstances. Pain and soreness in the neck are common during the first several days and can be managed with prescribed or over-the-counter pain medications.

Eating soft foods is recommended for the first few days, as swallowing may be uncomfortable. Examples include porridge, yogurt, smoothies, soft pasta, and soups. Gradually return to normal diet as comfort allows.

Most people return to work or school within one to two weeks, depending on their occupation and individual recovery. Those with physically demanding jobs may need additional time off. Complete healing of the surgical site takes several weeks, and you'll have follow-up appointments to ensure proper recovery.

Complications and Risks

Complications from neck cyst surgery are uncommon but can occur. As with any surgical procedure, there is a small risk of bleeding, infection at the surgical site, and adverse reactions to anesthesia. Specific risks related to neck cyst surgery include:

• Nerve injury: The neck contains several important nerves. Depending on the cyst location, there is a small risk of injury to nerves controlling tongue movement (hypoglossal nerve), facial movement (facial nerve branch), or shoulder movement (spinal accessory nerve).
• Recurrence: If the cyst or fistula tract is not completely removed, the condition can recur. Recurrence rates are generally low (less than 5%) with appropriate surgical technique.
• Scarring: While surgeons place incisions along natural skin creases to minimize visibility, some scarring is inevitable.
• Seroma or hematoma: Fluid or blood collection at the surgical site may require drainage.

Contact your surgical team if you experience any of the following after surgery: fever, increasing pain, spreading redness around the incision, drainage from the wound, or difficulty breathing or swallowing.

What Causes Neck Cysts and Fistulas?

Neck cysts and fistulas are caused by embryological remnants that fail to disappear during fetal development. Branchial cysts arise from branchial arch remnants, while thyroglossal duct cysts form from the thyroglossal duct remnants. These conditions are congenital (present from birth) and are not caused by anything during pregnancy.

Understanding the embryological origins of neck cysts helps explain why they occur and why they appear in specific locations. During early fetal development, the head and neck region forms through a complex process involving multiple embryological structures that normally disappear before birth.

Embryological Development

Between the third and eighth weeks of gestation, the human embryo develops a series of structures called branchial (or pharyngeal) arches. These arches are separated by grooves called clefts on the outside and pouches on the inside. The branchial apparatus is crucial for forming many structures of the head and neck, including parts of the face, ear, palate, tongue, thyroid, and parathyroid glands.

Normally, the branchial clefts and pouches obliterate (close and disappear) as development proceeds. When this process is incomplete, remnants can persist and eventually form cysts, sinuses (blind-ending tracts), or fistulas (tracts with both internal and external openings).

The thyroid gland begins its development at the base of the tongue and descends through the thyroglossal duct to its final position in the front of the neck. This duct normally closes and disappears by the tenth week of gestation. Persistence of any part of this duct can lead to thyroglossal duct cyst formation.

Why Do Some People Develop These Cysts?

The exact reasons why embryological remnants persist in some individuals but not others are not fully understood. These conditions are not caused by anything the mother did or didn't do during pregnancy. There is no known way to prevent them, and they are not the result of lifestyle factors or exposures.

In most cases, neck cysts occur sporadically without any family history. However, some studies suggest that certain types of branchial anomalies may have a genetic component, with higher occurrence rates in some families. Overall, the conditions are considered congenital anomalies that occur during the natural variation of human development.

How Do You Live With a Neck Cyst Before Surgery?

Many people live with small, asymptomatic neck cysts for years without problems. Monitoring for changes, avoiding trauma to the area, and recognizing signs of infection are key. If surgery is planned, following pre-operative instructions helps ensure the best outcome.

If you've been diagnosed with a neck cyst but surgery isn't immediately planned, there are several things to keep in mind for managing the condition and recognizing when intervention becomes necessary.

Monitoring Your Cyst

Pay attention to any changes in your cyst, including increases in size, new pain or tenderness, skin changes over the area, or any discharge. Keep track of when changes occur and what might have triggered them (for example, upper respiratory infections often cause temporary enlargement of branchial cysts).

Regular follow-up appointments with your healthcare provider allow for monitoring of the cyst over time. Your doctor may recommend periodic imaging studies to track any changes in size or characteristics.

Preventing and Recognizing Infection

While you cannot completely prevent infection, maintaining good general health may help reduce the risk. If you notice signs of infection—rapid swelling, pain, warmth, redness, or discharge—contact your healthcare provider promptly. Early treatment of infection with antibiotics can prevent complications and makes eventual surgical removal safer and more successful.

Preparing for Surgery

If surgery is scheduled, follow all pre-operative instructions carefully. This typically includes:

• Avoiding NSAIDs (like ibuprofen) for a week before surgery
• Not eating or drinking for a specified period before the procedure
• Arranging transportation home, as you cannot drive after anesthesia
• Preparing your home for recovery with soft foods and necessary supplies
• Taking time off work or school as recommended