What Is Ovarian Dermoid Cyst?

Ovarian dermoid cysts may contain fully developed tissues such as hair, teeth, and skin. While non-cancerous, they can lead to complications and are usually recommended for removal, especially when there's a risk of damaging the ovary or if they rupture.

Overview

Ovarian dermoid cysts, also known as mature cystic teratomas (MCT), are the most frequent non-cancerous ovarian tumours in adults and adolescents. These are fluid-filled sacs containing fully developed tissues such as hair, teeth, muscle, fat, and sometimes even brain or thyroid tissue.¹

Though sometimes asymptomatic, ovarian dermoid cysts can cause symptoms and have the potential to be malignant in 1-2% of cases over a person's lifetime. This risk can be reduced through cystectomy, the surgical removal of the cyst.^2,3 Dermoid cysts differ from most ovarian cysts as they do not develop in response to the menstrual cycle.

This article will delve into ovarian dermoid cysts, covering the potential causes, the symptoms individuals may undergo, the cysts' impact on the body, and the treatment strategies employed.

Prevalence of ovarian dermoid cysts

Dermoid cysts in the ovaries are the most common type of germ cell tumour. They make up about 70% of non-cancerous ovarian growths in individuals assigned female at birth (AFAB) of reproductive age and about 20% in those after menopause.¹
How do ovarian dermoid cysts affect the body?

Possible complications linked to dermoid cysts include:

• Torsion
• Rupture
• Infection
• Malignant transformation

Although these complications are uncommon.² 

Ovarian Torsion: As ovarian dermoid cysts grow, they can distort the shape of the ovary, leading to torsion. Without treatment, this twisting can harm or cause the ovary to lose its function.

Rupture: When these cysts rupture, their contents spill into the abdominal cavity. While most ruptured cysts are absorbed harmlessly, in certain instances, they can lead to infection, requiring urgent medical intervention. 

Dermoid cysts are typically harmless, but about 1–2% of cases may have cancerous areas called squamous cell carcinoma.²  

The tumour is at a higher risk of progressing into cancer if:

• You’re older than 45
• Have a rapidly growing tumour
• The tumour’s size exceeds 10 cm in diameter

Your healthcare provider might suggest removing the cyst to prevent potential risks such as rupture, twisting, or the development of cancer.

Symptoms and causes

Symptoms of ovarian dermoid cysts

Typically, ovarian dermoid cysts remain symptomless unless they reach a significant size. When symptoms do arise, they commonly involve sensations of pain, pressure, or a sense of fullness in the abdominal area.

Less frequent symptoms include:

• Nausea
• Vomiting
• Changes in bowel movement like constipation⁴
• Appetite changes
• Painful intercourse (dyspareunia)⁵

Causes of the development of ovarian dermoid cysts

It is not entirely known what causes this type of tumour. Reported risk factors may include:

• Late onset of menstruation
• Long duration of menstrual irregularities
• A history of cystic teratoma
• A reduced number of pregnancies
• Infertility
• Excessive drinking and exercise⁶ 

Why do ovarian dermoid cysts have uncommon elements like hair and teeth?

Ovarian dermoid cysts arise from germ cells - cells that typically form eggs or sperm - and contain tissues derived from all three germ cell layers - ectoderm, endoderm, and mesoderm. These layers play crucial roles in shaping distinct bodily structures and facilitating essential functions.

The ectoderm matures into crucial components such as skin, hair, and teeth, while the mesoderm contributes to muscle and connective tissue formation. Simultaneously, the endoderm plays a vital role in the development of essential internal organs, especially the gut.³ 

Sometimes, these layers develop irregularly, causing mature tissues to cluster and create a dermoid cyst. These cysts can consist not only of hair and teeth but also of various tissues derived from any of the three germ cell layers. 

Diagnosis and treatment

Ovarian dermoid cyst diagnosis

Ovarian dermoid cysts are often asymptomatic and are commonly discovered incidentally during routine imaging procedures, such as abdominal or transvaginal ultrasounds, typically used as part of standard check-ups or during pregnancy. Alternatively, they might be found during surgeries carried out for unrelated reasons.

Ultrasound can easily spot them because they have unique features that aren't typical in cancerous growths. A computed tomography scan (CT scan) and a magnetic resonance imaging (MRI) scan can also sometimes contribute to making a diagnosis. ^2,6  

Ovarian dermoid cyst structure 

Ovarian dermoid cysts can vary in size but usually have an average diameter of about 7 cm. They often contain diverse cell types derived from the three primary layers formed during early embryo development.

When observed under a microscope, ovarian dermoid cysts display a wall lining composed of cells resembling skin, while the exterior is covered by ovarian tissue. Inside, they typically have one chamber with small nodules, called Rokitansky nodules, which can contain hair, teeth, and other tissues.

The fluid within the tumour is known as sebaceous material; it is liquid inside the body but thickens at room temperature.

Almost all cases contain skin-like tissue (ectodermal tissue), while neural tissue (related to nerves and the nervous system) is found in fewer than half of the cases. Tissues like fat, bone, cartilage, and muscle (mesodermal tissue) are commonly present in more than 90% of cases, while tissues related to the digestive system (endodermal tissue) are less frequently seen.

In simple terms, these tumours are a mix of different tissues like fat, skin, hair, and sometimes teeth, all wrapped up inside a structure in the body.⁶  

Treatment of ovarian dermoid cysts

Unfortunately, the dermoid cyst does not go away without being surgically removed, unlike other cysts that disappear on their own. Treating ovarian dermoid cysts requires the surgical removal of the cyst and, in some uncommon instances, may involve removing the affected ovary. The chosen approach considers the severity of the cyst and factors like your plans to have children.

Ovarian cystectomy: This procedure removes the part of the ovary with the cyst while preserving your fertility.

Oophorectomy: Oophorectomy is the surgical removal of the entire ovary (or both) with the cyst. It's the usual treatment for AFAB individuals after menopause and some experts recommend considering this treatment before menopause, especially for patients who have multiple cysts in one ovary or a large dermoid cyst causing significant damage to healthy ovarian tissue.⁶  

Most surgeons remove ovarian dermoid cysts using laparoscopy or “keyhole surgery.” This type of surgery involves small, strategic incisions into your abdomen, reducing scarring, pain and bleeding after the operation. It also leads to a shorter hospital stay and a faster recovery time.

However, some criticise laparoscopy out of concern that it might cause the cyst to rupture, potentially increasing the chance of chemical peritonitis - an inflammation of the abdominal lining due to chemical irritation - and the formation of adhesions. Moreover, an incorrect diagnosis might result in the accidental release of malignant cells. ⁶

The surgeon may suggest a different type of surgery, known as laparotomy or open abdominal surgery, involving a larger incision, if your cyst is notably large, present in both ovaries or if there's a suspicion of it being cancerous. Depending on your unique case, the surgeon will advise you on the best options available.

FAQs

Is there anything I can do to lower my risk of an ovarian dermoid cyst?

Reducing your risk isn't possible as ovarian dermoid cysts develop before birth. 

Can a dermoid ovarian cyst cause weight gain?

No, it is uncommon to gain weight due to a dermoid ovarian cyst. However, if it’s large it can cause abdominal bloating and a feeling of pressure in this area. 4

Is a dermoid cyst an ectopic pregnancy?

No, a dermoid cyst is not an ectopic pregnancy and it does not increase the risk of having one. 7

Do dermoid cysts run in families?

Yes, but it is considered extremely rare and would affect the AFAB individuals in the family. 8

What happens if a dermoid cyst ruptures?

Although this does not happen often, the rupture of the dermoid cyst can result in inflammation of the peritoneum (the membrane surrounding internal organs of the abdomen). 9

Summary

Ovarian dermoid cysts, also known as mature cystic teratomas (MCT), are common non-cancerous growths that could contain fully developed tissues like hair, teeth, and even brain or thyroid tissue. While often asymptomatic, they can cause complications such as torsion, rupture, or, rarely, malignancy. These cysts differ from typical ovarian cysts as they don't form due to the menstrual cycle. They're most prevalent among assigned female at birth individuals of reproductive age, constituting about 70% of noncancerous ovarian growths. Complications like torsion or rupture can lead to severe pain or, in rare cases, infection. Although the risk of malignancy is low (1-2% of cases), factors like age, rapid growth, or large cyst size may elevate this risk. Diagnosis usually happens incidentally during routine check-ups or imaging tests like ultrasounds, revealing characteristic features. Treatment involves surgical removal, either through cystectomy (preserving the ovary) or oophorectomy (removing the affected ovary). Laparoscopy, a minimally invasive approach, is often preferred but may not be suitable for all cases, especially if malignancy is suspected or if the cyst is large or multiple. Understanding the symptoms, causes, diagnosis methods, and treatment options for ovarian dermoid cysts is crucial for timely intervention and management, considering the potential complications they may pose.