A dermoid cyst is a benign lump that forms beneath the skin when skin cells and related structures become trapped during early development before birth. It often appears as a slow-growing, painless swelling near the face, scalp or neck and may contain skin tissue, hair follicles and oil glands within the cyst.
A dermoid cyst is a benign (non-cancerous) growth that develops from cells present during early fetal development. These cells are capable of forming different types of body tissue. As a result, dermoid cysts may contain structures such as skin, hair follicles, sweat glands, oil (sebaceous) glands and sometimes teeth, cartilage or bone. Dermoid cysts are congenital, meaning they are present at birth. However, they may not be noticed until later in childhood or adulthood because they often grow slowly.
They most commonly occur:
Most dermoid cysts are harmless, but their location and size determine whether treatment is required.
Dermoid cysts form during early development in the womb. As tissues and structures form, small groups of embryonic cells can become trapped beneath the skin or in deeper tissues. These cells continue to grow slowly over time and produce normal body tissues in an abnormal location.
Dermoid cysts are not caused by infection, injury or lifestyle factors. They result from developmental changes before birth.
Many dermoid cysts cause no symptoms and are discovered during routine examination.
Common features include:
Symptoms depend on location:
Ovarian dermoid cysts can occasionally cause complications such as ovarian torsion (twisting of the ovary), which causes sudden severe pelvic pain and requires urgent treatment. Dermoid cysts may become inflamed or infected, leading to redness, tenderness and swelling.
Dermoid cysts are usually diagnosed through clinical examination and imaging.
A healthcare professional will assess:
Imaging tests may include:
Imaging helps determine the depth and extent of the cyst and whether it connects to deeper structures. If a cyst is removed surgically, it is usually sent for histological examination to confirm the diagnosis.
Not all dermoid cysts require immediate treatment. Observation may be appropriate if the cyst is small, not causing symptoms and shows no signs of rapid growth.
Surgical removal is usually recommended if the cyst increases in size, causes discomfort or cosmetic concern, interferes with nearby structures, is located in the ovary and causing symptoms, or if there is uncertainty about the diagnosis.
Complete surgical excision is the standard treatment, as removing the entire cyst wall reduces the risk of recurrence. Small superficial cysts are often removed under local anaesthetic, while deeper or ovarian dermoid cysts may require general anaesthetic. Many ovarian dermoid cysts can be treated using laparoscopic surgery. If infection is present, antibiotics may be required before definitive removal.
The outlook for dermoid cysts is generally very good.
Most dermoid cysts are benign, grow slowly and do not spread to other parts of the body. When a dermoid cyst is completely removed, recurrence is uncommon.
Complications are rare but can occur. For example, ovarian dermoid cysts may twist (ovarian torsion) or rupture, which requires urgent medical attention. Malignant transformation is very uncommon and has been reported in a small proportion of ovarian dermoid cysts, most often in adults later in life.
Early assessment and appropriate management help reduce the risk of complications and support an excellent long-term outcome.
Dermoid cysts cannot be prevented because they develop before birth as part of embryonic development. There are no known lifestyle or environmental risk factors. Regular medical review of new or changing lumps ensures timely diagnosis and treatment if needed.
If you have a dermoid cyst that is enlarging, becoming painful or causing concern, it is sensible to seek medical advice. We offer a free online skin and cyst assessment to provide personalised guidance and discuss appropriate treatment options tailored to your needs.
