Difference Between Ovarian Cysts & Polycystic Ovarian Syndrome (PCOS)

Polycystic ovarian syndrome (PCOS) is an endocrine disorder that impairs the normal functioning of the ovaries. PCOS is relatively common among women of childbearing age. According to a meta-analysis analysing 43 PCOS studies, the disease's estimated prevalence is approximately 6-10%.¹

While ovarian cysts and PCOS can have similar symptoms in some cases, they are two very different conditions. Women can have multiple ovarian cysts and not suffer from PCOS; however, multiple ovarian cysts are also a symptom of PCOS.

What is PCOS?

Women with PCOS often suffer from a hormonal imbalance where they produce a high amount of androgen, the male reproductive hormone. This imbalance affects the ovaries, which usually produce oestrogen and progesterone, two hormones crucial for maintaining the menstrual cycle. Consequently, the menstrual cycle gets disturbed, resulting in missed or fewer periods. 

According to the NHS, the exact cause is still uncertain, but abnormal hormone levels are thought to be the main contributing factor.² Insulin resistance is also thought to be associated with Polycystic ovarian syndrome.³ Several risk factors worsen insulin resistance with obesity being the most important. Insulin resistance, especially combined with obesity, can result in diabetes mellitus, fatty liver and obstructive sleep apnoea. All these conditions are associated with an increased risk of PCOS. 

According to the Rotterdam Criteria, the preferred diagnostic guideline for PCOS, two of the following criteria are required to make the diagnosis, namely:⁴

• Multiple Ovarian cysts, seen via ultrasound
• Menstrual cycle irregularities, with few or no ovulation
• Overproduction of androgens 

Symptoms related to the overproduction of androgens include male-pattern hair loss, acne and hirsutism, which is defined as excess thick pigmented hair in the male distribution, usually seen on the upper lip, chin, chest and lower abdomen, though this pattern varies according to race.

Difference between ovarian cysts and PCOS

The polycystic ovarian syndrome is a metabolic disorder associated with hormonal imbalance, excess androgen production and ovulation problems. Ovarian cysts are fluid-filled sacs in the ovary that do not necessarily alter the ovulation process. They can be asymptomatic and have no other associated complications.

Is polycystic ovarian syndrome (PCOS) treatable?

The main treatment goals for patients with Polycystic ovarian syndrome include management of the symptoms associated with high androgen levels, the underlying metabolic abnormalities and reduction of the risk of diabetes and other cardiovascular diseases. The treatment plan is also personalised to the patient, depending on the wish for pregnancy, and usually begins with lifestyle modifications. 

Lifestyle modifications

In general, diet and exercise to achieve weight loss are usually the first steps for overweight and obese women with PCOS. This would decrease symptoms associated with high androgen levels, insulin resistance and will also improve rates of fertility. Though the data on improvements in hirsutism is limited, even a mild 5-10% decrease in body weight can restore ovulation cycles.

Medications

Your doctor may recommend medical therapy to treat polycystic ovarian syndrome to regulate the menstrual cycle, ovulation, induce conception and decrease the risk of insulin resistance. Some of the commonly prescribed medications include:⁵ 

Birth control pills

Contraceptives help to restore the hormonal balance, which can help with menstrual irregularities and ovulation problems. Birth control pills may also be useful in treating acne and excess body hair that may be present. They are also crucial for reducing the risk of endometrial cancer, which can be a consequence of long-term hormonal imbalance.

Metformin

Metformin reduces the complications associated with insulin resistance. It restores ovulatory menses in approximately 30 to 50 percent of women with PCOS. It is usually given as a second line of therapy.

Ovulation inducing medications

For patients wanting to get pregnant, they may also be given various types of medications to induce ovulation. There are different types of medications that doctors may prescribe to induce ovulation with a stepwise approach to deciding which medication to give, each with its risks and benefits.

Hair removal treatment 

One of the characteristic features of PCOS is excessive hair growth. Certain medications, including birth control and antiandrogen pills, may be prescribed to women with PCOS to reduce unwanted hair growth.

Surgical options

When lifestyle changes and medical therapy fail to induce ovulation for patients wanting to get pregnant, patients may consider surgical options. Laparoscopic ovarian drilling (LOD) consists of internal heating or lasering of the ovaries to help reduce the production of androgens. Given the risks of the surgical procedure, however, medications are preferred over surgical options.

What is an ovarian cyst?

Ovarian cysts are fluid-filled sacs on the ovaries that can burst and cause sudden, sharp abdominal pain along with bleeding. Ovarian cysts are quite common among women who have regular periods. Sometimes, ovarian cysts can have no symptoms at all. Ovarian cysts can be 'functional', with a follicle developing during the menstrual cycle but not rupturing to release an egg. Ovarian cysts can also be caused by abnormal cell growths in the ovaries, both benign and cancerous, in addition to severe pelvic infections.

How is an ovarian cyst diagnosed?

Ovarian cysts are usually asymptomatic. Some women experience a dull ache in the lower abdomen on the side of the cyst which comes and goes. However, symptoms are usually more severe if the cyst ruptures, which may include:

• Sharp pelvic pain on the side of the cyst
• Painful sexual intercourse
• Painful bowel movements
• Nausea and vomiting
• Bloated or swollen abdomen

The presence of the above symptoms warrants a trip to the doctor's office to exclude complications associated with ovarian cysts. The doctor will then usually perform an ultrasound to view the ovaries and confirm the presence of the cysts. Additionally, a blood test to check for hormonal imbalance and CA-125 can provide further information about the possibility of endometriosis or ovarian cancer. As these are not routine check-ups, the doctor will decide which tests to perform based on the story and the physical examination.

Treatment of ovarian cysts

Treatment of ovarian cysts does not have to start immediately after a positive diagnosis. Your doctor may recommend waiting for a while before initiating therapy, as most ovarian cysts are of the functional type and will resolve on their own.  The treatment plan for ovarian cysts depends on the following criteria:⁶

• Whether the patient has reached menopause
• Presence or absence of symptoms
• Size and appearance of the cyst

After careful assessment of the criteria, the doctor may consider the following treatment:⁶

• The prescription of oral contraceptives to stop ovulation and thus prevent new ovarian cysts' progression and development;
• Measurements of CA 125, the cancer marker for ovarian cancer, to monitor the risk.
• Surgical removal of the cysts or oophrectomy if the cysts are large and are suspicious of cancer.

PCOS and ovarian cysts are two different conditions that are often confused. It is important to understand the differences between them. You should visit your gynaecologist or family doctor if you are experiencing any of the abovementioned symptoms. It may be a gynaecological or metabolic disorder or nothing to worry about, but visiting your doctor will give you the reassurance you need. 

References

1. Bozdag, G., Mumusoglu, S., Zengin, D., Karabulut, E., & Yildiz, B. O. (2016). The prevalence and phenotypic features of polycystic ovary syndrome: a systematic review and meta-analysis. Human Reproduction, 31(12), 2841-2855.

2. González, F., Considine, R., Abdelhadi, O., & Acton, A. (2019, March 1). Saturated fat ingestion promotes lipopolysaccharide-mediated inflammation and insulin resistance in polycystic ovary syndrome. Retrieved March 09, 2021, from https://www.ncbi.nlm.nih.gov/pubmed/30590569

3. NHS. (n.d.). NHS - Polycystic Ovarian Syndrome (PCOS) - Causes. Retrieved March 09, 2021, from https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/causes/

4. Rotterdam ESHRE/ASRM‐Sponsored PCOS Consensus Workshop Group. (2004). Revised 2003 consensus on diagnostic criteria and long‐term health risks related to polycystic ovary syndrome (PCOS). Human reproduction, 19(1), 41-47.

5. Yau, T. T., Ng, N. Y., Cheung, L., & Ma, R. C. (2017). Polycystic ovary syndrome: A common reproductive syndrome with long-term metabolic consequences. Hong Kong Medical Journal. doi:10.12809/hkmj176308

6. NHS. (n.d.). NHS - Ovarian Cyst - Treatment. Retrieved March 09, 2021, from https://www.nhs.uk/conditions/ovarian-cyst/treatment/