A dermoid cyst is a specific type of benign growth that is present from birth, though it may not become noticeable until later in life. Unlike some temporary fluid-filled sacs that may spontaneously resolve, dermoid cysts present a unique challenge due to their structural contents and origin. Understanding the biological nature of these growths is the first step in determining their prognosis and the need for medical management. This article will explore how these cysts form, whether they can disappear naturally, where they commonly occur, and when a doctor should intervene.
Understanding How Dermoid Cysts Form
Dermoid cysts are classified as congenital lesions, meaning they originate during the early stages of fetal development, specifically between the third and fifth weeks of gestation. This formation occurs due to the trapping of surface skin elements, known as ectoderm, during the process of embryonic fusion and closure. These trapped cells are incorporated into deeper tissues where they do not typically belong, forming a sac-like structure.
The cyst wall itself is lined with stratified squamous epithelium, a tissue nearly identical to the outer layer of skin. Within this wall are mature skin appendages, including hair follicles, sebaceous glands, and sweat glands. These structures continue to function normally, shedding skin cells and secreting an oily fluid called sebum into the enclosed sac. Over time, this accumulation of keratin debris, sebum, and sometimes hair, teeth, or even bone fragments, causes the cyst to slowly enlarge.
Do Dermoid Cysts Go Away on Their Own?
The definitive answer is that dermoid cysts do not go away on their own. Unlike functional ovarian cysts or simple fluid-filled sacs that the body can reabsorb, a dermoid cyst is a permanent structural malformation. The cyst contains mature, solid tissues, such as skin and its appendages, which means the body cannot naturally break down and eliminate the contents.
Because the lining of the cyst continues to produce secretions and shed cells, the growth will typically increase in size over the person’s lifetime. This slow, progressive accumulation of material within the sac is what drives its expansion. Since the structural components of the cyst are fixed and functional, removal of the cyst sac is the only way to eliminate the growth. Monitoring may be an option for small, asymptomatic cysts, but spontaneous resolution is not an expected outcome.
Common Locations and Manifestations
Dermoid cysts can occur anywhere in the body, but they have a strong predilection for areas where embryonic fusion lines occur. The head and neck region is the most common site, accounting for over 80% of cases, often appearing near the outer edge of the eyebrow (periorbital region). Superficial cysts in these areas typically manifest as a firm, non-tender, dough-like lump just under the skin.
Cysts can also form internally, with the ovaries and the spinal column being other well-known locations. An ovarian dermoid cyst, also known as a mature cystic teratoma, may cause pelvic pain, particularly if it grows large. Location dictates the potential for complications; for example, an ovarian cyst carries a risk of torsion, where the ovary twists and cuts off its own blood supply. Spinal dermoid cysts, which are very rare, can grow and compress the spinal cord or adjacent nerves, leading to neurological symptoms.
When Medical Intervention is Necessary
Since dermoid cysts do not resolve naturally, medical intervention often becomes a consideration for preventing complications or alleviating symptoms. Diagnosis typically involves imaging studies, such as ultrasound or Magnetic Resonance Imaging (MRI), to confirm the cyst’s contents and determine its exact size and depth. This imaging is crucial to distinguish a dermoid cyst from other types of growths that might resolve on their own.
For small, non-symptomatic surface cysts, a doctor may recommend careful monitoring with regular check-ups. However, the definitive management for any dermoid cyst that is growing, causing symptoms, or posing a risk of complication is surgical removal. The goal of surgery is the complete removal of the entire cyst sac. Removing the sac intact prevents the recurrence of the growth, as leaving behind any part of the secreting lining would allow the accumulation process to start again.