What Is a Dermoid Cyst?
A dermoid cyst is a round, rubbery lump under the skin. It begins during prenatal development (while a baby is developing in the womb), when healthy skin cells get trapped under the skin’s surface. These cells divide and grow, eventually forming into a ball of cells. Like all skin cells, they may produce hair, sweat and proteins.
After the baby is born, the dermoid cyst continues to grow. Dermoid cysts are not cancerous. But they can damage nearby tissue and bone. Dermoid cysts on the scalp may enter the skull and push on the brain’s surface.
Experts recommend removing dermoid cysts with surgery, typically at about 1 year of age.
Dermoid Cyst Symptoms
Dermoid cysts:
- Can occur anywhere on the body.
- Are most common on the scalp or near the eyebrows.
- Can be felt under the skin.
- Are usually subtle in appearance.
- Usually are not painful
- Do not typically grow larger than a quarter.
If your child has a lump on the skin that doesn’t go away, it’s important to get it checked out. Dermoid cysts grow slowly. Surgery is not urgent. But delaying care for too long could result in a more complicated surgery if the cyst has entered nearby tissue or bone.
Dermoid Cyst Types
Different types of dermoid cysts are named after their location in the body. The most common type of dermoid cyst is a periorbital dermoid cyst. Other types of dermoid cysts include cranial, epibulbar (or limbal), orbital, ovarian, periorbital, spinal and nasal dermoid cysts.
Cranial Dermoid Cyst
A cranial dermoid cyst is a rubbery bump between the skin and bone on an infant’s skull. It is present at birth. It is usually diagnosed within the first year of life, after it grows large enough to be seen and felt. The skin that covers a cranial dermoid cyst looks normal. Cranial dermoid cysts can occur anywhere on a child’s head, including on the face.
Experts recommend surgically removing a cranial dermoid cyst. Ideally, this happens when the cyst is small and has not grown into the skull bones or the brain’s dura mater (a layer of tissue that protects the brain). If the surgeon removes the cyst completely, the cyst is very unlikely to grow back.
Contact the Division of Plastic Surgery for more information.
Epibulbar Dermoid Cyst
An epibulbar dermoid cyst forms on the eye at the intersection (limbus) of the cornea (see-through window in the front of the eye) and sclera (white part of the eye). It appears as a white, full-thickness growth that straddles the limbus. Epibulbar dermoids are associated with Goldenhar syndrome, a rare condition that primarily affects eye, ear and spine development. They are sometimes called limbal dermoids.
An epibulbar dermoid cyst is present at birth and can grow slowly. Pediatric ophthalmologists (eye doctors) treat children with this condition. They cannot entirely remove the cyst with surgery. Doing so would damage the cornea and create an opening into the eye. Such an opening cannot be closed without creating problems much worse than the original issue.
If the cyst causes eye irritation, lubrication may help. Another option is for the ophthalmologist to shave down the cyst until it is level with the cornea surface and sclera. This procedure requires general anesthesia. It can be helpful when the elevated cyst is very irritating. It will probably not help with vision or eliminate any cosmetic concern associated with the cyst.
Contact the Division of Ophthalmology for more information.
Orbital Dermoid Cyst
Orbital dermoid cysts occur below the eyebrow and above the eyelid crease. They are usually on the outer part of the eye. These cysts are present at birth. They usually grow and become obvious during the first few years of life.
Orbital dermoid cysts can rupture (burst) and cause inflammation. This is why experts recommend surgery to remove them. The surgeon can make an incision (cut) in the eyelid crease, and remove the cyst through the incision. The scar from the incision is hidden in or looks like an extension of the eyelid crease. Once removed, orbital dermoid cysts do not grow back.
Contact the Division of Ophthalmology for more information.
Ovarian Dermoid Cyst
Ovarian dermoid cysts are also known as mature cystic teratomas. They grow slowly inside a female’s ovary. The main symptom is abdominal or pelvic pain. This may lead your child’s pediatrician to order magnetic resonance imaging (MRI). Sometimes, these cysts are discovered during an imaging test that was ordered for a different reason. When this happens, it is called an incidental finding. It is uncommon for a pediatrician to notice an ovarian dermoid cyst during a physical exam since the cysts are typically small.
If imaging results suggest there is an ovarian dermoid cyst, a pediatric gynecologist can help. When a cyst is small and not causing symptoms, the pediatric gynecologist may recommend follow-up imaging to watch it over time. The cyst will continue to grow. Eventually, the pediatric gynecologist will recommend surgery. The goal is to remove the cyst and keep the ovary intact. If the surgery goes well, the ovary will likely function normally. Fertility will not be affected.
In some situations, the pediatric gynecologist may need to remove the affected ovary due to the cyst’s location or size. This may have a less than 10% decrease in fertility later in life.
After surgery, the pediatric gynecologist may recommend follow-up ultrasound tests. The ultrasound is used to make sure that the ovarian dermoid cyst does not recur in the affected ovary or develop in the other ovary.
Contact the Division of Gynecology for more information.
Periorbital Dermoid Cyst
A periorbital dermoid cyst typically occurs under the skin near a child’s eyebrow. It is present at birth and starts out small. As it grows, you may be able to see and feel it. When the cyst is small, it is unlikely to block the child’s vision or cause other problems. It is important to remove these cysts to prevent them from becoming infected.
Pediatricians typically refer patients with a suspected periorbital cyst to a pediatric ophthalmologist or plastic surgeon. A computed tomography (CT) may be needed to confirm the diagnosis. If the cyst is removed completely, it will not grow back. The child’s eyebrow often hides the surgical scar.
Contact the Division of Ophthalmology for more information.
Spinal Dermoid Cyst
Spinal dermoid cysts are very rare. These cysts typically grow slowly, attached to the outside of the spinal cord. They usually are not visible to the eye and typically don’t create a bump you can feel.
Spinal dermoid cysts are most common in children who have other spinal conditions, such as myelomeningocele (a type of spina bifida). In these children, the cysts usually are diagnosed during pregnancy or right after birth during a medical imaging study (such as ultrasound). Very rarely, a spinal dermoid cyst is caused during a lumbar puncture or spinal surgery. Such cysts are often not discovered until they become large and cause symptoms, such as pain or difficulty walking.
If your child has a spinal dermoid cyst, a pediatric neurosurgeon can help. Removing the cyst is typically recommended. Spinal dermoid cysts cannot always be removed completely if they are near or touching a vital structure in the spinal cord. In this situation, the pediatric neurosurgeon will remove as much of the cyst as safely as possible. They will order follow-up imaging on a regular basis. The cyst may continue to grow. The child may one day need another surgery to reduce or remove it.
Contact the Division of Neurosurgery for more information.
Dermoid Cyst Diagnosis
Most dermoid cysts are diagnosed in childhood before the age of 5. About 40% of dermoid cysts are diagnosed at birth.
If the pediatrician believes your child may have a dermoid cyst, the next step is to see a pediatric surgeon, plastic surgeon or pediatric neurosurgeon. The specialist will examine the dermoid cyst and order imaging tests to learn more. Imaging can include a CT scan, MRI or both. If the cyst is located in the pelvic area, the specialist may order an ultrasound of the pelvis or vagina.
Imaging helps to:
- Confirm that the growth is a dermoid cyst.
- Rule out any concerning tumor types and infections.
- Know if the cyst has damaged surrounding tissue or is touching large veins. These things can complicate surgery.
Dermoid Cyst Removal
Experts recommend surgery to remove a dermoid cyst. In most situations, surgery should be done sooner rather than later. But if the child is younger than a year old, the surgeon may recommend waiting since the surgery requires general anesthesia.
Most of the time, surgery to remove a dermoid cyst is straightforward and takes about 30 minutes. Children usually go home the same day.
If the dermoid cyst has invaded bone or is located near a large vein, surgery will take longer. It may involve using bone cement or a titanium plate to rebuild damaged bone. The surgeon will admit the child to the hospital for a night for observation.
Children will return to the surgery clinic about two weeks after surgery for a wound check. They will see the surgeon in three months to ensure everything looks good. If the dermoid cyst occurred on a baby’s fontanel (soft spot), the surgeon might want to see the child about a year after surgery.
Dermoid Cyst Prognosis
After a dermoid cyst is removed with surgery, it is unlikely to grow back. Less than 5% of dermoid cysts recur after surgery.
