A dermoid cyst is a noncancerous growth that forms before birth when skin cells and other tissue get trapped during fetal development. What makes these cysts unusual is their contents: they can contain hair, skin, oil glands, sweat glands, and occasionally even teeth or bone fragments. They grow slowly, often go unnoticed for years, and are one of the most common types of cysts found in children and young adults.
The term “dermoid cyst” covers growths in several different parts of the body. Over 80% occur on the head and neck, but they also develop in the ovaries, on the spine, and rarely inside the brain or nose. The specific location changes how the cyst behaves, what symptoms it causes, and how it’s treated.
How Dermoid Cysts Form
During early pregnancy, the embryo develops distinct layers of tissue that eventually become skin, organs, bones, and the nervous system. Sometimes, small clusters of skin-forming cells get trapped in places where they don’t belong as these layers fold and fuse together. Those trapped cells continue to grow and produce the same materials they would on the body’s surface: skin, hair follicles, oil, and sweat glands. This is why a dermoid cyst can look startlingly complex when opened, containing mature tissues that seem completely out of place.
Because they originate during fetal development, dermoid cysts are typically present at birth or appear shortly after. Some, particularly ovarian dermoid cysts, may not be detected until adulthood when they’ve grown large enough to cause symptoms or show up on an imaging scan done for another reason.
Where Dermoid Cysts Occur
The most common type is a periorbital dermoid cyst, which forms near the outer edge of one eyebrow. These are the cysts pediatricians most frequently see in infants and young children. They appear as a small, firm, painless lump under the skin that you can usually move slightly with your fingers. The lump may be skin-colored or have a faint yellow tinge, and a tiny pit or opening on the surface sometimes produces a small amount of yellow or white drainage.
Other locations include:
- Ovaries: Ovarian dermoid cysts (also called mature cystic teratomas) are the most common type in women of reproductive age. They grow inside or on the surface of an ovary.
- Spine: Spinal dermoid cysts form along the spinal column and, while rare, can press on nerves as they grow.
- Brain: Intracranial dermoid cysts are rare and may cause headaches or neurological symptoms depending on their size and position.
- Nose: Nasal sinus dermoid cysts form inside the nasal passages.
- Eye surface: Epibulbar dermoid cysts grow on the surface of the eye itself.
Symptoms of Ovarian Dermoid Cysts
Most ovarian dermoid cysts don’t cause any symptoms unless they grow large. When they do, the most common complaint is pain, pressure, or a feeling of fullness in the lower abdomen. Less frequently, they cause nausea, vomiting, constipation, appetite changes, or pain during intercourse.
The more serious concern with ovarian dermoid cysts is torsion, where the weight of the cyst causes the ovary to twist on itself, cutting off its blood supply. A review of over 1,000 cases at a single institution found torsion occurred in about 5.6% of cases, with larger cysts carrying a higher risk. Torsion causes sudden, severe abdominal pain (often on the lower right side), nausea, vomiting, dizziness, or fever. It’s a surgical emergency that requires immediate treatment to save the ovary.
Are Dermoid Cysts Cancerous?
The vast majority are completely benign. Malignant transformation in an ovarian dermoid cyst occurs in only 1% to 2% of cases, and it’s more likely in older women with larger cysts. Superficial dermoid cysts on the head, neck, or face carry an even lower risk. Still, any new or growing lump should be evaluated, because imaging and sometimes tissue analysis are the only ways to confirm what a cyst actually is.
Surgical Removal and What to Expect
Surgery is the standard treatment for dermoid cysts regardless of location. Because these cysts don’t resolve on their own and tend to grow slowly over time, removal prevents them from reaching a size where they cause pain, infection, or complications like torsion.
For cysts on the face and head, surgeons often use techniques designed to minimize visible scarring. Cysts near the eyebrow can sometimes be removed through an incision hidden in the eyelid crease. Cysts on the forehead may be accessed through small incisions placed above the hairline. Minimally invasive approaches have also been used successfully for cysts in harder-to-reach locations like the tongue or the floor of the mouth.
Ovarian dermoid cysts are typically removed with minimally invasive surgery (laparoscopy), which uses small incisions in the abdomen. More than 70% of ovarian cases in one large review were treated this way, with fewer complications compared to traditional open surgery. The main trade-off is a higher chance of the cyst spilling its contents during removal. While cyst spillage sounds alarming, it rarely causes problems. Among 394 patients who experienced spillage in that review, only one developed chemical peritonitis, an inflammatory reaction in the abdominal lining.
Cysts in the brain or spinal cord require more specialized neurosurgical techniques, sometimes guided by advanced imaging to map out nearby nerve pathways and minimize damage to surrounding tissue.
Recurrence After Surgery
Most dermoid cysts don’t come back after removal, but recurrence is possible, particularly with minimally invasive surgery. In adults, the recurrence rate after laparoscopic removal is around 4%, compared to essentially 0% after traditional open surgery. The difference likely comes down to how completely the cyst wall can be removed through a smaller incision.
In adolescents, recurrence rates tend to be slightly higher, around 10% after cystectomy. However, most recurrences are small and found incidentally on follow-up ultrasound rather than causing new symptoms. Only about 3% of adolescent patients with recurrence needed a second surgery. Your surgeon may recommend periodic imaging after removal to monitor for any regrowth, especially if the cyst was in the ovary and fertility preservation was a priority during the initial operation.