A dermoid cyst is a sac-like growth, present from birth, that contains tissues typically found on the outer layer of the body, such as skin and glands. This congenital mass is essentially a pocket of normal tissue that has developed in an unexpected location, often appearing just under the skin. As a benign anomaly, the dermoid cyst is a common subject of inquiry: will these growths naturally disappear over time?
Why Dermoid Cysts Do Not Resolve
The biological reason a dermoid cyst cannot resolve spontaneously lies in its origin and composition. Dermoid cysts are congenital, developing early during fetal development when layers of skin and associated structures become trapped beneath the surface. This misplaced tissue, derived from the ectoderm, continues to function normally within the enclosed sac.
Unlike a simple fluid-filled cyst that the body might reabsorb, the dermoid cyst contains mature, living components, such as hair follicles, sweat glands, and sebaceous glands. These glands actively produce and secrete materials like hair, sebum (skin oil), and dead skin cells. The continuous accumulation of this material causes the cyst to grow slowly over time, rather than shrink or disappear.
Because the cyst wall is lined with skin-like tissue, it behaves like a miniature, internal patch that is constantly exfoliating and secreting. This ongoing process means the body has no mechanism to break down and clear the contents of the cyst. Therefore, surgical removal is the only definitive way to eliminate a dermoid cyst.
Common Locations and Associated Symptoms
Dermoid cysts can appear anywhere in the body, but they are most frequently found in the head and neck region, accounting for over 80% of cases. Superficial cysts, such as those near the eyebrow, typically present as a painless, firm, and dough-like lump just beneath the skin. They can range in size from half a centimeter up to six centimeters in diameter.
The symptoms of a dermoid cyst depend heavily on its specific location. Superficial cysts may cause cosmetic concern. If they press on bone, they can cause the adjacent bone to grow irregularly. If a superficial cyst ruptures or becomes infected, it can lead to noticeable swelling, inflammation, and pain in the surrounding tissue.
Internal dermoid cysts, such as those found on the ovaries, called mature cystic teratomas, can pose more significant health risks. While they are often asymptomatic and discovered incidentally, they can grow large enough to cause pelvic pain and pressure. A serious complication of an ovarian dermoid cyst is ovarian torsion, where the weight of the cyst causes the ovary to twist, cutting off its blood supply and resulting in sudden, severe abdominal pain.
Cysts in the spinal cord or within the skull are less common but require immediate attention due to their proximity to delicate neurological structures. A spinal dermoid cyst may press against the spinal cord or nerves as it grows, leading to neurological symptoms. Their gradual expansion can damage nearby structures, necessitating prompt intervention.
When Medical Intervention is Necessary
Since a dermoid cyst will not spontaneously resolve, medical professionals often recommend surgical excision as the definitive management approach. This procedure removes the cyst and its contents, including the sac lining, which is necessary to prevent recurrence. For many superficial cysts that are not causing symptoms, a period of observation may be considered.
The decision to remove a cyst is frequently made to preempt potential complications that can arise from leaving the growth in place. The primary risks of non-intervention include the possibility of the cyst becoming infected, which requires urgent treatment. There is also the risk of rupture, which can cause severe inflammation as the internal contents leak into surrounding tissues.
The growth of a cyst can eventually lead to compression of nearby structures, which is a particular concern in locations like the spine or near the eye socket. For ovarian dermoid cysts, removal is often recommended when the cyst exceeds a certain size, typically around five centimeters, or if it is causing symptoms. Timely removal is a protective measure that prevents most of the serious complications.