Ovarian Dermoid Cysts: Do They Cause Irregular Periods?

Most of the time, ovarian dermoid cysts (also called mature cystic teratomas) do not cause irregular periods, missed periods, or hormonal symptoms. While the ovaries themselves naturally produce hormones, a typical dermoid cyst does not usually produce or interfere with reproductive hormones ^[1][2].

Because it is very understandable to connect a new ovarian diagnosis with a change in periods, many people assume their dermoid cyst is the reason for skipped periods, acne, or unexpected weight changes. However, if you are experiencing these symptoms, they are often unrelated to the cyst. Your doctor should evaluate your cycle changes separately, as the true cause cannot be determined from symptoms alone.

Symptoms a Dermoid Cyst Can Cause

Dermoid cysts are a type of usually benign (non-cancerous) tumor that forms from reproductive cells. They are unique because they can develop into different types of body tissue, such as skin, hair, fat, or even teeth. Many dermoid cysts cause no symptoms at all and are discovered incidentally during an ultrasound for another issue ^[1].

When a dermoid cyst does cause symptoms, it is almost always due to its size and the physical space it takes up, not hormones. You might experience:

• Pelvic or abdominal pain ^[3]
• A feeling of pressure or fullness in the abdomen ^[2]
• A palpable mass (a lump that a doctor can feel during an exam), if the cyst grows large enough ^[4]

When to Seek Emergency Care
If a cyst grows, it can cause the ovary and its blood supply to twist. This is a medical emergency known as ovarian torsion. While larger cysts increase this risk, torsion can happen with masses of various sizes ^[5][3]. A cyst can also uncommonly rupture, causing severe irritation in the pelvis ^[6][2].

Go to the nearest emergency room immediately (do not wait for a routine appointment) if you experience:

• Sudden, severe, or worsening pelvic or abdominal pain (often on one side)
• Pain accompanied by nausea, vomiting, fever, or fainting
• Severe pain alongside a positive pregnancy test or a missed period, which could indicate a medical emergency like an ectopic pregnancy (a pregnancy outside the uterus)

Why Are My Periods Irregular?

If your dermoid cyst is unlikely to be causing your irregular bleeding or hormonal symptoms, what is? There are many reasons for a change in your menstrual cycle. Some common causes include:

• Pregnancy: If pregnancy is possible, a missed period should prompt you to take an at-home pregnancy test.
• Polycystic ovary syndrome (PCOS): A very common condition that causes irregular periods and symptoms like acne or excess hair growth.
• Thyroid disorders: An underactive or overactive thyroid gland.
• Medications: Hormonal birth control, certain antidepressants, or other medications.
• Lifestyle factors: High stress, major weight changes, eating disorders, or intense exercise.
• Perimenopause: The natural, multi-year transition into menopause.
• Elevated prolactin: High levels of the hormone responsible for milk production.

The Very Rare Exceptions

In exceptional case reports, the tissues inside an ovarian teratoma can affect a person’s hormones. These situations are very rare and are not typical of an ordinary dermoid cyst:

• Androgen production: In extremely rare, case-report-level exceptions, a dermoid cyst can contain cells that produce androgens (hormones made in people of all sexes, such as testosterone). This can lead to missed periods, excess facial or body hair, and severe acne ^[7][8][9].
• Thyroid hormone production: A specialized, rare type of teratoma called struma ovarii is made mostly of thyroid tissue. While the presence of thyroid tissue does not always mean it is producing clinically significant hormone levels ^[10], in very rare instances, it can cause symptoms of an overactive thyroid (hyperthyroidism) ^[11][12].

If you have a dermoid cyst along with signs of hormone imbalance, do not assume the cyst is the only cause. Work with your doctor to investigate your cycle changes through targeted testing based on your specific symptoms and medical history.