Simple cysts are relatively common and usually clear on their own. Complex cysts are more likely to need treatment.
Most ovarian cysts are benign, meaning that they are noncancerous.
In this article, we take a close look at complex ovarian cysts, including their causes, symptoms, and treatments.
What is a complex ovarian cyst?
Ovarian cysts are small sacs that form in or on an ovary. Ovarian cysts can be simple or complex, depending on the substances that are inside them.
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.
Most cysts are not harmful. According to the Office of Women’s Health (OWH), cancerous cysts are rare and more common in older women.
The different types of complex ovarian cyst include:
- Endometriomas. This type occurs when the cells of the uterine lining grow in or around the ovaries or on the uterus. Endometriomas contain a thick brown fluid.
- Dermoids. Skin, hair, fat, or teeth cells make up dermoid cysts.
- Cystadenomas. These cysts are made of ovarian tissue and contain mucus or fluid.
A person with complex ovarian cysts may not experience any symptoms. People may only discover them during medical exams for other conditions or symptoms.
If complex ovarian cysts do cause symptoms, people may notice the following:
- pressure or bloating in the abdomen
- general pain in the lower abdomen
- vomiting or nausea if the cyst causes the ovaries to bend or twist
- an urgent or frequent need to urinate if the cyst pushes on the bladder
- a severe pain that comes on rapidly if the cyst bursts
If a person has endometriomas, they may have additional symptoms that include:
- pain during sex
- pain during periods
- issues with fertility
- pain during bowel movements or urination
People should see their doctor if they experience severe pain in the abdomen, a fever, and vomiting.
Causes and risk factors
In many cases, medical experts do not know what causes complex ovarian cysts.
A condition called endometriosis causes endometriomas. Endometriosis is when the cells of the uterine lining grow outside of the uterus.
Women who ovulate are most at risk for developing an ovarian cyst. Meanwhile, after menopause, ovarian cysts are more likely to develop into ovarian cancer.
In many cases, a cyst will clear on its own without treatment. However, if a doctor suspects that someone has an ovarian cyst, they will typically conduct a pelvic examination.
A doctor may perform an ultrasound scan to identify the type and location of any cysts. They may take blood samples to look for proteins that might indicate if a person has cancer.
Complications of complex ovarian cysts may include the following:
- If a cyst grows too large, it can press against the bladder, causing a frequent need to urinate.
- An enlarged cyst may also push the ovary out of its usual position in the body.
- An ovarian cyst can cause ovarian torsion, where the ovary twists. This action may be very painful.
- A person may develop fertility issues because of cysts on the ovaries.
- In rare cases, ovarian cysts can develop into ovarian cancer.
If a cyst ruptures or hemorrhages, a person may experience severe symptoms, including:
- nausea and vomiting
- severe pain
- fast breathing
- abnormal vaginal bleeding
Complex cysts are more likely to need treatment than simple cysts.
According to the OWH, between 5–10 percent of women with ovarian cysts will have surgery. Of that number, between 13–21 percent are cancerous.
A doctor may recommend surgery when a cyst is becoming too large, interfering with the ovary or other organs, or is painful.
A surgeon will often use laparoscopy to remove an ovarian cyst. Here, the medical team places the individual under general anesthesia, and the surgeon performs keyhole surgery, using small entry points, to remove the cyst.
Most complex ovarian cysts are benign and may not cause any symptoms. A person may experience pain or discomfort if the cyst grows too large.
An enlarged cyst may push against the bladder, cause abdominal pain, or interfere with fertility. Full recovery is usual when a person requires surgery.
If someone suspects that they have an ovarian cyst, they should speak to their doctor to find out the best course of action.