What Causes a Dermoid Cyst, and Are They Hereditary?

When you are diagnosed with a dermoid cyst, it is completely normal to wonder where it came from, whether you did something to cause it, and if you might pass it on to your children. The short answer is no—there is no evidence that anything you did caused your dermoid cyst, and most of them are not inherited ^[1].

The term “dermoid cyst” can refer to different types of growths depending on where they are located. They generally form due to early developmental or cell-growth errors, not because of your lifestyle. Depending on whether you have a congenital skin cyst or an ovarian dermoid, the exact reason it formed is different.

Why Do Congenital Dermoid Cysts Form?

Congenital dermoid cysts typically form on the face, scalp, neck, or spinal area. Congenital means that the cyst was present during development or at birth; it does not mean that the condition was passed down genetically.

These cysts develop before you are even born. During the early weeks of fetal development, the different layers of tissue that will become your body’s structures must fold and fuse together ^[2]. Sometimes, surface skin cells (ectoderm) get trapped along these embryonic fusion lines ^[3][4].

Because these trapped cells belong to the skin, the cyst lining may contain skin structures that produce keratin, sebum (oil), or hair ^[2]. Since these substances have nowhere to go, they collect inside a sac. Even though you are born with a congenital dermoid, it can take years for the cyst to collect enough material to become large enough to notice ^[5][6].

Why Do Ovarian Dermoid Cysts Form?

Ovarian dermoids, medically known as mature cystic teratomas, form differently. These benign cysts develop from germ cells—the specialized cells in the ovary that are meant to mature into eggs ^[7][8].

Instead of normal development, an ovarian egg cell (oocyte) undergoes abnormal activation, and its genetic material is duplicated ^[9]. Because a germ cell contains the ability to develop into various tissues, the resulting cells can develop into mature tissues such as skin, hair, fat, bone, or teeth ^[10][11]. This cyst is not an embryo, is not caused by sexual activity or pregnancy, and does not mean you did anything wrong ^[9].

Did I Do Anything to Cause My Dermoid Cyst?

There are no known routine lifestyle factors that cause dermoid cysts to form. Specifically, there is no medical evidence that ordinary daily activities cause these cysts, including:

• Your diet or weight ^[9]
• Sexual activity, sexually transmitted infections, or birth control methods ^[9]
• Poor hygiene ^[9]
• Exercise or typical physical activities ^[9]
• Typical pregnancy activities your mother did before you were born ^[2]

Direct trauma or injury does not cause typical congenital or ovarian dermoid cysts. (In rare cases, traumatic injury or surgery can implant skin cells deep into tissue, creating what is called an acquired epidermal inclusion cyst, which is sometimes confused with a congenital dermoid). However, physical trauma or prolonged pressure can sometimes cause an existing ovarian dermoid cyst to rupture, which can lead to sudden severe pelvic pain and requires immediate medical attention ^[9].

Are Dermoid Cysts Hereditary?

Most dermoid cysts occur sporadically, meaning they happen by chance and do not run in families ^[1].

While familial clustering (where multiple family members have ovarian teratomas) has been reported, it is highly uncommon and does not establish a standard inherited pattern for most people ^[1][12].

In very rare instances, multiple dermoid cysts or dermoids in specific locations can be associated with larger genetic conditions. For example, a presacral dermoid cyst (located at the base of the spine) combined with specific sacral and anorectal abnormalities may prompt testing for a rare condition like Currarino syndrome ^[13]. A midline spinal lesion might also need assessment to ensure it does not connect to the spinal canal ^[14]. Your clinician might suggest a genetic evaluation or specialized imaging if you have multiple congenital anomalies, a characteristic presacral lesion, or a well-documented family pattern of teratomas ^[15][13]. For the average person, a single dermoid cyst is an isolated occurrence.