Ovarian Cysts


If you are a woman within the age range of 13 – 50 and you’re told that you have an ovarian cyst you need to take a deep breath and stop thinking that you’re going to die of ovarian cancer.

Ovarian cysts are common and are one of the leading reasons that women seek help from their gynecologists. Often they produce symptoms of lower abdominal pain. Other symptoms associated with them include distention, abnormal menstrual bleeding or pain during intercourse. However, with the large number of ultrasound examinations, CT scans and MRIs that are performed—often for reasons other than pelvic pain– we see an increasing number of patients that are referred from their primary care doctors or radiologists that have been told that they have an ovarian cyst or cysts. These women often have no symptoms other than the tremendous anxiety that may have cancer or infertility.

The reality of ovarian cysts is that every woman who ovulates gets them—because a cyst is critical to the development of an egg as well as the hormones estrogen and progesterone. Unfortunately, there are some abnormal ovarian cysts but the overwhelming majority of them are benign. Rarely, there are ovarian cancers that occur in this age group—very rarely. The reality is that most ovarian cysts are physiologic and a few are pathologic.

Diagram of Ovarian Cyst in left ovary and where the ovaries are in the female human body.

A physiologic cyst is one that serves a purpose in reproductive function—it’s where your eggs are made and where the hormones estrogen and progesterone are made. For that reason physiologic ovarian cysts are also called functional ovarian cysts. These cysts appear and disappear as you progress from one menstrual cycle to the next.

Pain sometimes accompanies physiologic ovarian cysts. Cysts occur as part of every menstrual cycle—but most women do not experience pain during every menstrual cycle. The reasons why some cysts cause pain and others don’t are complex but here are some of them:

Larger ovarian cysts are more likely to cause pain even though larger ones aren’t any more “dangerous” than smaller ones.

Larger cysts may be more likely to “leak” fluid—and that can cause pain

In most cases, however, it simply isn’t clear why some women experience pain some of the time but not at others.

Pathologic cysts serve no reproductive or hormonal function; all they do is to scare you. In most cases they need to be removed. Usually an ultrasound examination can tell the difference between a physiologic (functional) ovarian cyst and a pathologic cyst (one that should be removed).

How do physiologic (functional) ovarian cysts occur?

As I already said these are also called functional ovarian cysts—because they serve a function! Here’s how they occur. In the early part of your menstrual cycle—beginning with the onset of your period—your eggs are already maturing and being selected for you next ovulation. The next ovulation often occurs 14 days after the onset of your period. During that 14 day stretch from the first day of your period until ovulation several small cysts start to grow on your ovary. These look like tiny little balloon structures and vary from ¼ inch to an inch in diameter. During a typical cycle your ovaries may grow several of these cysts—as many as a dozen—but only 1 or 2 will actually mature enough to ovulate and produce a mature egg ready for ovulation. The fluid within this little “balloon” contains estrogen. So you see that the cyst in the early part of your menstrual cycle serves at least two functions—first, it’s where your eggs grow and second it’s where estrogen production occurs.

After these cysts get to a certain size—around an inch in diameter—they rupture. This is called ovulation!

Notice the hole to the right portion of the ovary. This is where ovulation occurred and the egg passed into the fallopian tube. That’s why we often refer to physiologic (functional) ovarian cysts that occur prior to ovulation as “ovulation cysts”. These cysts can be painful as many women experience some pain as these cysts are enlarging and getting ready to “pop” (ovulate).

After ovulation, something miraculous happens. The very cyst where the egg grew—which is now collapsed and empty for a short while—starts to fill in with blood vessels and that “ovulation” cyst starts producing cholesterol–you see, a certain amount of cholesterol isn’t a bad thing!

The cholesterol undergoes a chemical change and becomes the hormone progesterone. Progesterone is made in another type of physiologic cyst called a corpus luteum cyst. Corpus is the Greek work for “body” and “lutea” means “yellow”. These cysts are often yellow in color because of the cholesterol (which is a fat) in them. The purpose of progesterone is to nurture an early pregnancy. If a pregnancy doesn’t occur during that cycle the cyst dissolves and your next menstrual period starts about 2 weeks after ovulation and about 4 weeks since the onset of your previous menstrual period. Occasionally, these corpus luteum cysts can grow quite large—3 to 4 inches in diameter. At that size they’re bigger than your uterus. They can be quite painful and scary—especially if at the same time you’re worrying about something like cancer! The good news is that these cysts go away by their selves. It may take a week or two but they disappear as your body is getting ready for the next cycle.

Cysts are easily seen on ultrasound examination—and that’s how we diagnose them. It’s quite simple to see them. On ultrasound exam solid structures (like your uterus which is mostly muscle) show up in different shades of grey. Cysts are filled with fluid and all fluids show up on ultrasound as black.

There are at least 5 cysts (some small and one big one). The cysts are black in appearance. The intervening grey structure is the rest of the ovary.

Ultrasound of at least five cysts in a uterus.

Notice how this ovary is made up of several small “black balloons” with one dominant one—the largest one. These are all individual cysts—however, only the largest of these is likely to “ovulate” and produce an egg, while the others shrivel (a process called atresia). In this case one can easily count at least 5 cystic cavities (follicles) on this single ovary. From experience I can tell you with great certainty that this most likely represents an ovulation cyst—one that occurs just prior to ovulation. Remember that ovulation cysts (also called follicular cysts) produce two things: eggs and estrogen.

The point is that both of these kinds of cysts happen in every woman virtually every cycle during her reproductive years—even if she is taking oral contraceptives. Corpus luteum cysts last about 14 days before they dissolve and allow the next cycle to begin. Should pregnancy occur, the corpus luteum cyst, which produces progesterone, will sustain the early pregnancy throughout the first trimester (12 weeks) and becomes known as the corpus luteum of pregnancy.

So let’s review:

Cysts can be either:

Physiologic (also called functional) – one kind occurs prior to ovulation and is called an ovulation or follicular cyst. Another kind occurs after ovulation and is called a corpus luteum cyst

With few exceptions physiologic cyts go away on their own and don’t require surgery.

Or Pathologic – these are abnormal and generally do not go away by their selves.

What is a pathologic ovarian cyst?

These cysts don’t serve a function–the majority of them occur in women under 50 and are benign. There are many different kinds of pathologic ovarian cysts – most are benign. You may have heard of some of these.

Endometriomas. These cysts form in women who have endometriosis—a whole other subject for a future newsletter. Endometriosis occurs when tissue that normally lines the inside of the uterus grows outside the uterus—often on the surface of the uterus, bowel, bladder or ovaries. When the tissue becomes attached to the ovary it tends to grow rapidly and can produce large ovarian cysts. These cysts can produce pain, infertility and even make it difficult to have sex.

Cystadenomas. These cysts form from cells on the outer surface of the ovary. They are often filled with a watery fluid or thick, sticky gel. They can become large and cause pain. Most often, however, these cysts do not cause pain unless they twist or rupture.

Dermoid cysts. These cysts contain many types of cells. They may be filled with hair, teeth, and other tissues that become part of the cyst. They too are generally painless but can become large and often show up on either a pelvic examination or a routine ultrasound.

Polycystic ovaries. These cysts are caused when eggs mature within the “little balloons” but are not released. The cycle then repeats. The sacs continue to grow and many cysts form. Women with polycystic ovaries often have other issues which may include irregular periods and infertility.

What are the symptoms of an ovarian cyst?

Symptoms of ovarian cysts (physiologic or pathologic) include:

  • pressure, swelling in the abdomen
  • pelvic pain
  • dull ache in the lower back and thighs
  • problems passing urine completely
  • pain during sex
  • pain during your period
  • abnormal bleeding
  • breast tenderness
  • nausea and vomiting

What do I do if I’m told I have an ovarian cyst?

The best thing to do is try and talk to your health care provider as soon as possible. Generally, she or he will assure you that your cyst is most likely benign and often you’ll be given a “best guess” that the cyst is functional (physiologic) and will likely disappear on its own. It’s easy to say don’t panic—but try not to. Remember that the vast majority of cysts between the ages of 13 and 50 are normal structures that you make in the process of ovulation and hormone production. Most ovarian cysts will not cause future problems though they may certainly cause inconvenience. Only a very small number of them will require intervention—surgery.