Dermoid Cysts

What Are They, Causes, Treatment, and More

Author: Lily Guo, MD

Editor: Alyssa Haag, MD

Editor: Emily Miao, MD, PharmD

Editor: Kelsey LaFayette, DNP, ARNP, FNP-C

Illustrator: Abbey Richard, MSc

Modified: Apr 08, 2026

What are dermoid cysts?

Dermoid cysts are benign (i.e., non-cancerous) subcutaneous lesions that can occur anywhere on the body but are most commonly found on the head and neck, inside the skull, on the lower back, and in the ovaries. Ovarian dermoid cysts are also referred to as cystic teratomas and contain mature tissue (e.g., skin, hair follicles, sweat glands, teeth, bone, or cartilage). On the head, the most common areas for dermoid cysts include the lateral upper eyelid, lateral forehead, and the submental region, or under the chin. The most common area on the skull for these growths to occur is the anterior fontanelle which is the largest fontanelle at the top of the head and is also known as the bregma after it closes at 18-36 months. Dermoid cysts are considered to be congenital, but not all of them are diagnosed at birth.

What causes dermoid cysts?

Dermoid cysts occur due to abnormal alterations in fetal development. As the embryo develops, the ectoderm, one of the three primary layers of embryonic cells, may become trapped along the lines of embryonic closure. The exact mechanism of why these tissues become trapped is not fully understood at this time. The ectoderm layer forms structures including skin, hair, and nails, thereby causing dermoid cysts, if this layer is disrupted during development.

What are the signs and symptoms of dermoid cysts?

The signs and symptoms of dermoid cysts include a rubbery, often solitary, subcutaneous nodule that is typically 1 to 4 centimeters (cm) in diameter. Dermoid cysts are noncompressible, non-tender, and appear skin-colored or bluish. While they may be present at birth, only about 40% of dermoid cysts are diagnosed at birth, while about 60% of dermoid cysts are diagnosed by five years of age. The delay in diagnosis can be attributed to the fact that dermoid cysts grow slowly and are typically asymptomatic. They can be discovered incidentally, especially as the cyst grows. If symptoms do occur, they may include a visible lump or mass, and discomfort or pain if the cyst becomes inflamed or ruptured. In rare cases, complications related to the cyst's impact on nearby structures (e.g., vision problems for cysts near the eye) may occur.

How are dermoid cysts diagnosed?

Dermoid cysts are typically diagnosed through physical examination, followed by imaging studies to confirm their presence and determine their exact size and location. Ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI) are commonly used imaging techniques. In some cases, a biopsy may be performed to rule out other conditions (e.g., lipoma, pilar cyst), although it is not preferred as cyst manipulation may lead to complications (e.g., infection), and the characteristic appearance of dermoid cysts usually makes them identifiable through imaging alone. A biopsy of a dermoid cyst shows a well-defined wall lined by stratified squamous epithelium, the tissue comprising the outer layer of skin; the lumen may be filled with hair follicles, sebaceous glands, and eccrine (i.e., sweat) glands.

How are dermoid cysts treated?

Dermoid cysts often do not require treatment aside from monitoring since they are largely benign and asymptomatic. Surgical removal may be recommended if the cyst is causing symptoms, if there is a risk of rupture, or to prevent potential complications. Surgery aims to remove the cyst wall and its contents completely to avoid recurrence. If a dermoid cyst on the skin is infected and fluctuant (i.e., contains pus) it can be treated with incision and drainage and systemic antibiotics (e.g., cephalexin, doxycycline). Excision should be delayed until the infection has subsided. For cysts in sensitive areas, such as in the skull or ovaries, the procedure is often performed by specialists including general surgeons, neurosurgeons, or obstetrics and gynecological surgeons. Removal of a dermoid cyst usually leads to a full recovery without long-term complications.

What are the most important facts to know about dermoid cysts?

Dermoid cysts are benign subcutaneous lesions that can appear anywhere on the body, with a higher prevalence on the head and neck, inside the skull, on the lower back, and in the ovaries. They contain mature tissue, such as skin, hair follicles, and sometimes teeth or bone. Symptoms, when present, include a visible, often solitary nodule that is rubbery and non-tender. Dermoid cysts can potentially lead to discomfort or complications if inflamed or ruptured. Diagnosis involves physical examination and imaging techniques like ultrasound, CT scans, and MRI, with biopsies occasionally used to confirm the diagnosis. Treatment for dermoid cysts is typically not required especially if the cysts are asymptomatic and not in sensitive areas. For symptomatic cysts or those at risk of complications, surgical removal can be conducted, ensuring the entire sac and its contents are excised.

Key Takeaways

Definition	Benign subcutaneous lesions, most commonly found on the head and neck, lower back, and ovaries, containing mature tissue elements, most commonly skin appendages such as hair follicles and sebaceous glands.
Locations	- Ovary: ovarian dermoid cysts (cystic teratomas) - Head: - Lateral upper eyelid - Lateral forehead - Submental region - Skull: anterior fontanelle
Causes	- Abnormal alterations during fetal development - Ectoderm entrapment along lines of embryonic closure - Ovarian dermoid cyst: all three germ layers involved
Signs and Symptoms	- Nodules appear: - 1-4 cm in diameter - Rubbery - Non-compressible - Non-tender - Skin-colored or bluish - Slow-growing, usually asymptomatic (→delayed diagnosis) - If symptomatic: - Discomfort or pain (inflamed/ruptured cyst) - Damage to nearby structures (e.g., vision problems)
Diagnosis	- Physical examination - Imaging (ultrasound, CT scan, MRI) - Biopsy (to exclude other conditions; not routine) - Cyst wall: stratified squamous epithelium + hair follicles, sebaceous glands - Lumen: hair shafts and keratin
Treatment	- Monitoring - Surgical removal if: symptoms; risk of rupture; potential complications - Incision and drainage + antibiotics for infected cysts

References

Bommaji SB, Qureshi MY, Reddy GS, Rampati S. Submental dermoid cyst mimicking double chin. Niger J Surg. 2019;25(2):217-219. doi:10.4103/njs.NJS_36_18

Prior A, Anania P, Pacetti M, et al. Dermoid and epidermoid cysts of scalp: case series of 234 consecutive patients. World Neurosurg. 2018;120:119-124. doi:10.1016/j.wneu.2018.08.197

Stone MS. Cysts. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2017:1917-1918.