What are ovarian cysts?


What are ovarian cysts? — Anatomically, a woman’s reproductive organs are composed of a uterus, a left and right Fallopian tube attached to the uterus and a left and right ovary underneath the Fallopian tubes. Sometimes, fluid can fill up a growth within an ovary creating an ovarian cyst. In women who are having their monthly period, the ovaries release an egg about once a month. In women over 40 years old who learn they have ovarian cysts, the first concern is the possibility for cancer although in reality, worry about cancer when they learn they have cysts. But most of the time, cysts are not cancer.

How frequently do we find ovarian cysts in women?

Simple cysts are filled with fluid. Monthly ovulation will often include the formation of cysts, and they are not usually a cause for concern. When they cause no problems, they are called functional cysts.
Complex cysts are less common than simple cysts. Either blood or a hard substance fills complex cysts. Unlike simple cysts, complex cysts are not related to the typical menstrual cycle.
The reported prevalence of ovarian cysts in women is between 8% and 18% of women although not all ovarian cysts need surgery . 1
In the U.S., only 5% to 10% of women undergo surgery for ovarian cysts in their lifetime and only 13% to 21% of these cysts are malignant.2

What causes ovarian cysts? — There are many possible causes of ovarian cysts. The most common causes of simple cysts include:

Ovulation – Ovulation is when an egg is released from the ovary each month. For this to happen, the ovary grows a sac, called a “follicle.” Sometimes, a follicle grows but does not release an egg and instead forms a cyst.

Corpus Luteum Cyst – if a woman gets pregnant after the egg is released, a cyst can stay on the ovary for weeks or months. It is formed on the ovary at the site of a follicle, or sac, that has matured and released its ovum or egg, in the process known as ovulation. The corpus luteum is made up of lutein cells (from the Latin luteus, meaning “saffron-yellow”), which develop immediately following ovulation, when yellow pigment and lipids accumulate within the granulosa cells lining the follicle. It may, however, fill with fluid or blood, causing the corpus luteum to expand into a cyst, and stay in the ovary. These kinds of cysts are not harmful and usually go away on their own especially if the patient is not pregnant. It may persist in pregnancy to produce progesterone and support the pregnancy until the placenta takes over the production of Progesterone to support the pregnancy.

Hemorrhagic Corpus Luteum Cyst – this is an ovarian cyst that develops because of occurrence of bleeding into a follicle or corpus luteum.3

Polycystic ovary syndrome (also called PCOS) – In women with this condition, the ovary grows many small cysts, instead of 1 big follicle that goes away each month. These cysts usually do not go away, but the cysts themselves do not need to be treated or removed. Treatment is mainly medical to address the insulin resistant problem and anovulation

The different types of Complex Ovarian cysts are the ff:

Dermoid cysts – These are a common type of cyst. They sometimes have teeth, hair, or fat in them. That might sound strange. Dermoid cysts are normally not harmful to your health, but your doctor might want to remove them with surgery.

Hemorrhagic Corpus Luteum Cyst – this is an ovarian cyst that develops because of occurrence of bleeding into a follicle or corpus luteum.3,4

Cystadenomas.These cysts are made of ovarian tissue and contain mucus, called mucinous cystadenomas or serous fluid called serous cystadenomas.

Endometriosis – Endometriosis is a condition where tissue normally found in the lining of woman’s uterus called endometrium, implants outside of the uterus, like in the ovaries, the back or the front of the uterus or anywhere in the abdominal cavity, producing endometriotic implants. Thus, when a woman bleeds during menstruation, she also bleeds into those implants outside the uterus causing pelvic pain during their periods or at other times, pain in the belly during sex, or trouble getting pregnant. Endometriotic cysts in the ovary are filled with blood that look like chocolate syrup. Hence, they are also called “chocolate cysts”.

Ovarian Cancer – Cancer is the cause of ovarian cysts in less than 1 in 100 cases. Ovarian cancer is most likely to affect older women who have been through menopause (no longer have a monthly period) or who have a family history of ovarian cancer. This “silent” cancer is most often discovered and treated when it has already spread, contributing to a reported 5-year survival rate of only 33% to 46%.5-7 Ideally, ovarian cancer would be found and removed while still confined to the ovary, when the 5-year survival rate is greater than 90%.
Unfortunately, there does not seem to be a precursor lesion for most ovarian cancers, and there is no good way of finding it in the stage 1 phase, so detecting this cancer before it spreads remains an elusive goal.5,8

What are the symptoms of ovarian cysts? — Many women have no symptoms. Sometimes, they are only discovered on routine physical exam or ultrasound.
The usual symptoms are the following:

  • pressure or bloating in the abdomen
  • general pain or right or left pain in the lower abdomen
  • abnormal vaginal bleeding
  • vomiting or nausea or pain if the ovarian cyst or twists
  • frequency or urgency of urination if the cyst pushes on the bladder
  • a sudden, severe, unbearable stabbing pain if the cyst ruptures, prompting emergency room consult

In the case of endometriomas, a patient may have the following additional symptoms that may include:

  • constipation
  • diarrhea
  • painful intercourse (called dyspareunia)
  • nausea
  • pain during periods (called dysmenorrhea)
  • fertility problems
  • pain during bowel movements (called dyschezia) Immediate consult should be made if you experience severe pain in the abdomen, fever and vomiting.

How do we test for ovarian cysts?

Imaging tests – The most common kind is a pelvic, vaginal or transrectal (it still a virgin) ultrasound. This test uses sound waves to create a picture of your uterus and ovaries, map out the location, size and if it is attached or adherent to the uterus or intestines. An Ultrasound with a Doppler can map out the flow in the blood vessels to differentiate a benign from a malignant tumor. An MRI or a CT scan may also be ordered and correlated with the findings on ultrasound.

Blood tests to check for pregnancy or check for elevation of certain tumor markers like CA-125, CEA, HE-14, BHCG, which may raise the suspicion of cancer.

How are ovarian cysts treated? — Treatment depends on the type of cyst and what your symptoms are. Possible treatments include:

Watchful Waiting – The cyst may be simply observed, if small and asymptomatic with an ultrasound every couple of months. Your cysts might stay the same size, get smaller, or even go away. In those cases, you usually don’t need to do anything to treat them.

Birth control pills and other types of hormone-like pills – This medicine can stop some types of new cysts from growing and may even shrink some endometriomas.

Surgery to remove a cyst is called Oophorocystectomy while removal of the whole ovary is called Oophorectomy. The type of surgery will depend on the size of the tumor, as well as desire for fertility. Cysts up to 5 cm in size may be removed laparoscopically, depending on the surgeon’s skill and experience. Larger cysts may be removed by open surgery or minimally invasively by Robotic Surgery.

  1. Greenlee RT, Kessel B, Williams CR, et al. Prevalence, incidence, and natural history of simple ovarian cysts among women >55 years old in a large cancer screening trial. Am J Obstet Gynecol 2010; 202:373.e1-e9
  2. NIH Consensus Development Panel on Ovarian Cancer. NIH consensus conference. Ovarian cancer. Screening, treatment, and follow-up. JAMA 1995; 273:491–497
  3. N. Yoffe, M. Bronshtein, J. Brandes, Z. Blumenfeld. Hemorrhagic ovarian cyst detection by transvaginal sonography: the great imitator. Gynecol Endocrinol, 5 (1991), pp. 123-129
  4. Jain KA. Sonographic spectrum of hemorrhagic ovarian cysts. J Ultrasound Med 2002; 21:879–886.
  5. Clarke-Pearson DL. Clinical practice. Screening for ovarian cancer. N Engl J Med 2009; 361:170–177.
  6. National Cancer Institute. Surveillance Epidemiology and End Results (SEER). Cancer statistics on ovarian cancer. http://seer.cancer.gov/statfacts/html/ovary.html. Accessed May 9, 2013.
  7. American Cancer Society. Survival by ovarian cancer stage. www.cancer.org/Cancer/OvarianCancer/DetailedGuide/ovarian-cancer-survival-rates. Accessed May 9, 2013.
  8. Brown PO, Palmer C. The preclinical natural history of serous ovarian cancer: defining the target for early detection. PLoS Med 2009; 6:e1000114