Ovarian Cysts: Types, Symptoms, Causes, Diagnosis & Treatment Options

In short: Ovarian cysts are collections of fluid in or on the ovary, common in the reproductive years; the most frequent is the follicular cyst, and others include the corpus luteum cyst and endometriosis cysts. They may cause irregular periods, pelvic pain or bloating. Treatment depends on the type: follow-up by ultrasound, hormonal pills or surgical removal. Sudden sharp pain needs urgent attention.

What Is an Ovarian Cyst?

• An ovarian cyst is a fluid-filled sac that forms within or on the surface of the ovary.
• The ovaries are two small organs located on either side of the uterus. They produce hormones such as estrogen, which helps regulate menstruation.
• Each month, the ovary is designed to produce an egg, which is important for fertilization.
• A normal follicle can reach 2-3 cm before ovulation; a fluid sac larger than about 3 cm is called an ovarian cyst, and these can vary in size from small to quite large.
• The majority of ovarian cysts are benign (non-cancerous) and harmless.
• Ovarian cysts can occur at any age, but they are most common during the childbearing years.

Types of Ovarian Cysts

1- Functional cyst (the most common type), which is usually short-lived and resolves on its own.

2- Pathological cyst, which may be benign (harmless) or malignant (cancerous).

Signs and Symptoms of Ovarian Cysts

• Symptoms:

Many patients with ovarian cysts experience some form of pelvic or abdominal pain.

Signs:

Your doctor will need to investigate to determine the exact cause of your symptoms.

• In most cases, ovarian cysts are small, benign, and cause no symptoms or signs at all.
• Other conditions can cause similar symptoms to an ovarian cyst, including pelvic inflammatory disease, ectopic pregnancy, ovarian cancer, appendicitis and diverticulitis.

Common Signs and Symptoms Include:

1- Irregular menstruation.

2- Pelvic pain, either persistent or intermittent, before menstruation begins or before it ends.

3- Pain during sex.

4- Pain during bowel movements.

5- Pressure on the bowel and bladder.

6- Pregnancy-like symptoms such as breast tenderness or nausea.

7- Bloating and swelling.

8- Difficulty fully emptying your bladder.

9- Loss of appetite.

10- Hormonal changes which may affect the breasts and body hair growth.

Symptoms That Need Immediate Medical Attention:

1- Sudden, severe pelvic or abdominal pain — this may be due to torsion (the cyst twisting on its pedicle and cutting off blood supply), or a ruptured cyst.

2- Pain accompanied by fever and vomiting.

3- Any concern that the cyst may be cancerous.

Causes of Ovarian Cysts

Functional Ovarian Cysts

There are two types:

1- Follicular Cyst

This is the most common type of ovarian cyst. Normally, every month the ovary produces one egg, which forms inside a follicle containing fluid that protects the growing egg. Each month, the follicle is meant to burst and release the egg into the tube, on its way to the uterus for possible fertilization. When the follicle doesn’t release the egg, fluid can build up and form a follicular cyst, which usually resolves on its own without treatment.

2- Luteal Ovarian Cyst

After the egg is released, the remaining tissue is called the corpus luteum, which normally shrinks over time. If it fills with blood instead, it can form a hemorrhagic corpus luteal cyst, which usually disappears on its own within a few months. However, in some cases it may rupture and cause significant pain or bleeding.

Pathological Cysts

1- Dermoid cyst (cystic teratoma):

This is the most common pathological cyst in women under 30. It is usually benign and arises from totipotent germ cells. These cysts can contain tissue such as teeth, hair, skin, and bone, and typically need to be removed surgically.

2- Cystadenomas:

These cysts develop from the outer layer of the ovary and are filled with either thick mucus or a watery fluid.

• They may grow inside the ovary or be attached to it by a stalk.
• They are rarely cancerous but usually need to be removed surgically.

3- Endometriosis:

This type of cyst affects patients with endometriosis, a condition where endometrial-like tissue grows outside of the uterus. In these cases, surgical removal is often needed.

4- Polycystic ovary syndrome:

These are not true cysts but many small, harmless follicles (immature eggs) that stop growing because of a hormonal imbalance; they do not need to be removed.

Possible Complications of Ovarian Cysts

• Many cysts cause no symptoms and are discovered incidentally during an exam or scan.
• Cysts that develop after menopause deserve closer evaluation, as they carry a higher chance of being cancerous.
• Some cysts may:

Rupture:

This can cause sudden, severe pain and may lead to internal bleeding.

Become Twisted (Torsion):

If the ovary becomes enlarged, it may shift position and twist over its pedicle, cutting off blood supply and causing severe pain — this requires urgent medical attention.

What Causes Ovarian Tumors?

• If the tumor is non-cancerous, it is called benign. If it is cancerous, it is called malignant and requires prompt medical care.

Types of Ovarian Tumors

1- Epithelial cell tumors, which arise from the outer surface layer of the ovary. These are the most common type of ovarian tumor.

2- Germ cell tumors, which are mostly benign and arise from the cells that produce the egg.

3- Stromal tumors, which arise from the cells that produce ovarian hormones.

Risk Factors for Ovarian Cancer

1- Age, especially after menopause.

2- Smoking.

3- Obesity.

4- Infertility (fertility medications themselves have not been shown to clearly increase the risk of ovarian cancer).

5- Hormone replacement therapy.

6- Never having given birth, or never having breastfed.

7- A family history of ovarian, colorectal, endometrial or breast cancer (including carriers of BRCA gene mutations or Lynch syndrome), and a history of endometriosis.

Oral contraceptives may help reduce the risk of ovarian cancer.

How Ovarian Cysts Are Diagnosed

• If an ovarian cyst is suspected, your doctor may recommend further testing to determine its type and the most appropriate treatment plan:

1- Pregnancy Test:

If the pregnancy test is positive, ultrasound should first confirm that the pregnancy is inside the uterus and ectopic pregnancy has been ruled out before assuming the cyst is a corpus luteum cyst related to early pregnancy.

2- Pelvic Ultrasound:

This is a painless procedure in which a probe is gently introduced vaginally, allowing us to evaluate the uterus and both ovaries. This helps determine the size and consistency of any cyst — whether it is fluid-filled (usually benign), contains solid material, or is mixed, which would need further evaluation to rule out cancer. Specialists use standard scoring systems (such as IOTA or O-RADS), and in women after menopause the scan is combined with CA-125 to calculate a risk score that decides whether referral to a gynaecological cancer team is needed.

3- Laparoscopy:

This involves a thin telescope inserted through a small incision in the abdomen, allowing the doctor to directly visualize the uterus, ovaries, and tubes. If a cyst is found, it can often be removed laparoscopically during the same procedure.

4- CA-125 Blood Test:

This protein can be elevated in cases of ovarian cancer, but it can also rise due to several benign conditions such as endometriosis, uterine fibroids, and pelvic inflammatory disease — so it is not used alone to diagnose cancer.

5- CT scans, MRI, and PET scans may be ordered in cases where cancer is suspected, to help determine the extent of the disease.

Treatment of Ovarian Cysts

Treatment Depends on Several Factors:

1- The age of the patient.

2- Whether the patient is pre- or post-menopausal.

3- The appearance of the cyst.

4- The size of the cyst.

5- Any symptoms caused by the cyst.

A- Observation:

1- Most functional cysts disappear on their own within 8-12 weeks, especially in premenopausal patients with a cyst measuring 2-5 cm.

2- Simple cysts smaller than 5 cm usually need no follow-up; if a scan repeat is needed, it is usually done after 6-12 weeks (after one or two periods), and cysts of 5-7 cm are often checked yearly.

3- In postmenopausal women, monitoring with ultrasound alongside CA-125 levels is recommended. Any change in size or texture may require prompt evaluation. A small simple cyst with a normal CA-125 is usually rechecked with ultrasound and CA-125 after 4-6 months; if it disappears, or stays unchanged for one year, no further follow-up is needed.

4- During this time, it may help to limit caffeine and alcohol and drink plenty of water to help ease symptoms.

B- Birth Control Pills:

These do not shrink an existing cyst, but they may help prevent new cysts from forming in patients who tend to develop them frequently.

C- Surgery for Ovarian Cysts

Surgery may be recommended in the following situations:

1- Complex ovarian cysts that persist over several months.

2- Persistent, symptomatic cysts lasting over 2-3 menstrual cycles.

3- Simple ovarian cysts larger than about 7 cm, or those that keep growing.

4- Cysts in postmenopausal women that are larger than 5 cm, complex, growing, or associated with a raised CA-125 (small simple cysts with normal CA-125 can usually be monitored).

5- If the cyst appears suspicious or potentially cancerous.

• There are two main types of surgery:

Laparoscopy:

• Two to three small incisions are made in the abdominal skin, a telescope is introduced through one of them, and the cyst is removed and sent for histopathology (lab analysis).
• This method offers a faster recovery. The surgeon aims to keep as much healthy ovarian tissue as possible, but removing some cysts (especially endometriosis cysts) can reduce the ovary’s egg reserve, so this is discussed before surgery in women who plan pregnancy.

For background on egg supply and how it is assessed, see our article on ovarian reserve.

Laparotomy:

• This more extensive surgery is used if the cyst is cancerous. When cancer is suspected, the operation should be done by a gynaecological cancer specialist, usually through a vertical incision in the middle of the abdomen so the whole abdomen can be examined. Depending on how far the tumor has spread, the doctor may need to remove the other ovary, the uterus, and nearby organs.
• If cancer is confirmed, additional treatment may be needed depending on the extent and type of the tumor.

1- Chemotherapy:

Medications given intravenously, orally, or directly into the abdomen to help destroy cancer cells — though they can also affect healthy cells. Possible side effects include nausea, vomiting, hair loss, kidney effects, and increased risk of infection.

2- Radiotherapy:

This uses high-energy x-rays to target and destroy cancer cells, but it is rarely used for ovarian cancer today. Side effects can include skin redness, nausea, diarrhea, and fatigue.

3- Maintenance treatment:

After chemotherapy, many women receive maintenance tablets (PARP inhibitors such as olaparib or niraparib) or bevacizumab (an infusion), especially if they carry a BRCA mutation.

Can Ovarian Cysts Be Prevented?

• There is no medication that fully prevents cyst formation, but regular follow-up can help catch and manage complications early.
• Oral contraceptives may help prevent follicular cysts specifically (this type only).

If you are experiencing symptoms of an ovarian cyst or would like a professional evaluation, Dr. Najeeb Layyous and his clinical team are available to discuss your individual situation and recommend appropriate next steps.

Dr Najeeb Layyous F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist