Ovarian Cysts

Definition | Types | Aetiology | Risk Factors | Clinical Presentation | Investigations | Management | When to Refer | References

Definition

Ovarian cysts are fluid-filled sacs that develop in or on the ovaries. They are common, particularly in women of childbearing age, and are often benign and asymptomatic.

Types

Ovarian cysts can be broadly categorised into functional and pathological cysts:

• Functional Cysts: The most common type, related to the menstrual cycle. These include:
  • Follicular Cysts: Occur when a follicle does not release an egg and continues to grow.
  • Corpus Luteum Cysts: Form when the corpus luteum fills with fluid after releasing an egg.
• Pathological Cysts: Less common, not related to the menstrual cycle. These include:
  • Dermoid Cysts (Mature Cystic Teratomas): Contain tissues such as hair, skin, or teeth, as they arise from germ cells.
  • Endometriomas: Caused by endometriosis, where endometrial tissue grows outside the uterus, including on the ovaries.
  • Cystadenomas: Develop from ovarian tissue and can contain mucus or serous fluid.

Aetiology

The development of ovarian cysts depends on their type:

• Functional Cysts: These arise from normal ovarian function and are influenced by hormonal changes during the menstrual cycle.
• Pathological Cysts: Their development can be due to conditions like endometriosis (endometriomas), or arise from abnormal cell growth, as in the case of dermoid cysts and cystadenomas.

Risk Factors

Several factors can increase the likelihood of developing ovarian cysts:

• Hormonal Imbalances: Including those related to fertility treatment or irregular menstrual cycles.
• Pregnancy: Cysts can develop in early pregnancy and often resolve on their own.
• Endometriosis: Women with endometriosis are at higher risk of developing endometriomas.
• Previous Ovarian Cysts: Women who have had ovarian cysts before are more likely to develop them again.
• Polycystic Ovary Syndrome (PCOS): A condition characterised by multiple small cysts on the ovaries.

Clinical Presentation

Ovarian cysts are often asymptomatic and may be discovered incidentally during imaging for other reasons. When symptoms do occur, they may include:

• Pelvic Pain: A dull or sharp ache in the lower abdomen, often on one side.
• Bloating or Abdominal Fullness: Feeling of heaviness or pressure in the abdomen.
• Pain during Intercourse: Discomfort or pain during sexual activity.
• Changes in Menstrual Cycle: Irregular periods, heavier or lighter than usual bleeding.
• Frequent Urination: If a cyst presses on the bladder.
• Acute Pain: Sudden, severe pain if a cyst ruptures or causes ovarian torsion (twisting of the ovary).

Investigations

If an ovarian cyst is suspected, the following investigations are typically performed:

• Pelvic Ultrasound: The primary imaging tool used to assess the size, shape, and composition (solid or fluid-filled) of a cyst.
• Transvaginal Ultrasound (TVUS): Provides a more detailed view of the ovaries and helps in assessing cysts more clearly.
• CA125 Blood Test: This test measures the level of CA125, a protein that can be elevated in ovarian cancer. It is more commonly used in postmenopausal women to assess the risk of malignancy, although it is not specific and can be raised in benign conditions.
• MRI or CT Scan: May be used for further evaluation if the ultrasound findings are unclear or if malignancy is suspected.
• Pregnancy Test: To rule out an ectopic pregnancy in reproductive-aged women presenting with pelvic pain.

Management

The management of ovarian cysts depends on their type, size, and the presence of symptoms:

Observation and Follow-Up

For functional cysts or small, asymptomatic cysts, a “watchful waiting” approach with repeat ultrasounds is often appropriate, as many cysts resolve on their own.

Medical Management

• Hormonal Contraceptives: While they do not shrink existing cysts, they can help prevent the formation of new cysts by regulating the menstrual cycle.
• Pain Management: NSAIDs such as ibuprofen can be used to manage pain associated with ovarian cysts.

Surgical Management

Surgery may be recommended in the following situations:

• Persistent Cysts: Cysts that do not resolve after several menstrual cycles or are increasing in size.
• Symptomatic Cysts: Cysts causing significant pain or other symptoms that impact quality of life.
• Suspicion of Malignancy: Cysts with suspicious features on imaging or elevated CA125 levels may require removal for histopathological examination.
• Ovarian Torsion: This is a surgical emergency requiring immediate intervention to untwist the ovary and preserve ovarian function.

When to Refer

Referral to a gynaecologist is warranted in the following situations:

• Persistent or large cysts (>5cm), particularly in postmenopausal women.
• Complex cysts with solid components or suspicious features on ultrasound.
• Elevated CA125 levels, particularly in postmenopausal women.
• Severe symptoms such as acute pain, suggesting complications like torsion or rupture.
• Uncertainty about the diagnosis or the need for further evaluation.

References

1. NHS (2024) Ovarian Cysts. Available at: https://www.nhs.uk/conditions/ovarian-cyst/ (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Ovarian Cysts: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/ng476 (Accessed: 26 August 2024).
3. British Medical Journal (2024) Management of Ovarian Cysts in Primary Care. Available at: https://www.bmj.com/content/359/bmj.j2035 (Accessed: 26 August 2024).

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