A dermoid cyst is a growth present at birth, containing tissues typically found on the outer layers of the skin. These cysts can include components like skin, hair follicles, and sebaceous glands. They are essentially a sac of normal tissue located in an unexpected part of the body.
Understanding Dermoid Cysts
Dermoid cysts are benign, non-cancerous growths. They are congenital, forming during fetal development, though they may not be noticeable until months or even years after birth.
The cysts are lined with stratified squamous epithelium and can contain various mature tissues, such as hair, skin, sweat glands, and oil glands. In some cases, more complex tissues like bone, teeth, or cartilage can also be present, particularly in ovarian dermoid cysts.
These cysts can appear almost anywhere on the body, but they are most frequently found in the head and neck region, accounting for approximately 84% of cases. Common specific locations include around the eyes (periorbital area), on the scalp, and in the neck. They can also occur internally, such as on the ovaries or along the spine. Typically, dermoid cysts present as slow-growing, painless lumps.
How Dermoid Cysts Form
Dermoid cysts originate from a developmental anomaly during the early stages of fetal growth. They form when ectodermal elements, which normally develop into skin and its appendages, become trapped along embryonic closure lines. This entrapment occurs as different layers of tissue are forming and fusing, typically between the 3rd and 5th weeks of gestation.
These misplaced cells continue to behave as normal skin cells would, producing substances like keratin, oil, and sweat. The accumulation of these secretions, along with shed skin cells and hair, causes the cyst to gradually enlarge over time. This process is a result of a localized error in embryonic development. The exact reasons why this developmental error occurs are not fully understood.
Are Dermoid Cysts Directly Inherited?
In the vast majority of instances, dermoid cysts are not directly inherited from parents. Their formation is considered a sporadic developmental error that happens during embryogenesis, meaning it is typically an isolated event and not a genetic trait passed down through families. While dermoid cysts are congenital, this does not imply a direct hereditary link.
Dermoid Cysts and Genetic Syndromes
Although dermoid cysts themselves are not inherited, they can occasionally be a feature within certain rare genetic syndromes. In such cases, the underlying genetic syndrome is inherited, and the dermoid cyst appears as one of many associated symptoms.
For example, dermoid cysts, particularly those affecting the eye (epibulbar dermoids), are observed in some individuals with Goldenhar syndrome. Goldenhar syndrome is a rare congenital disorder characterized by craniofacial anomalies, and dermoid cysts can be part of its manifestation due to related embryological origins.
Other rare conditions might also include dermoid cysts as part of a complex set of symptoms. These associations are exceptions to the general rule that dermoid cysts are sporadic developmental anomalies. While some studies suggest a possible genetic predisposition for ovarian dermoid cysts within families, further research is needed to fully understand this connection.