“You have a cyst”. Those words spoken by the gynecologist invoke thoughts of cancer, surgery, or hysterectomy, along with a sense of terror. Unfortunately, gynecologists usually are not particularly adept at allaying these fears. Fortunately, however, the vast majority of “cysts” discovered during pelvic exams or ultrasounds in premenopausal women are destined to resolve spontaneously if we just leave them alone. Most are “functional” cysts that are the result of normal ovulatory function.
Generally speaking, the term “cyst” refers to a growth within the ovary that is filled with fluid. The fluid might be very thin and watery or thick and viscous. This characteristic can usually be appreciated by transvaginal ultrasound. Both benign and malignant tumors can also be “cystic”. The term “tumor” usually refers to a growth within the ovary that is solid, with little or no fluid component. Some ovarian masses have both solid and cystic components.
An overview of ovarian “cysts” must be divided into two segments: premenopausal and postmenopausal. “Cysts” in these two groups of women differ significantly in etiology, diagnosis, and treatment.
“Cysts” in Premenopausal Women
In a normal menstrual cycle, one (or occasionally both) ovaries begin to enlarge shortly after the onset of menses. By day 10 to 14 of the cycle, a dominant follicle (cyst) has developed. This “cyst” can be 4 centimeters or more in diameter. By the time of ovulation, it can be larger. Should a pelvic exam or transvaginal sonogram be done at this time, a “cyst” will be found. It is a normal, natural process. At the time of ovulation, the follicle (cyst) ruptures and an egg (oocyte) is released. This can be associated with bleeding inside the abdomen and pain. Once ovulation has occurred, the remaining “cyst” is called a corpus lutean. It is an entirely normal and natural “cyst”. Unfortunately, when a corpus lutean cyst is seen on sonogram, it can be very unusual in appearance, displaying both solid and cystic components. This sonographic appearance is caused by varying amounts of blood contained within the cyst.
When a cyst “ruptures”, it is usually a follicle that has released an egg along with a few ounces of follicular fluid. If the follicle ruptures through a blood vessel (which is not uncommon), blood accumulates in the pelvis and is usually associated with a lot of pain. The pain can be severe and acute, but is almost always self-limited. This is usually called a “hemorrhagic” cyst. It is completely normal and rarely requires surgery. Corpus lutean cysts will virtually always resolve (heal) spontaneously if left alone. Unfortunately, this is one of the most common reason for surgical removal of ovaries and ovarian cysts in premenopausal women. When a corpus lutean cyst or a simple functional cyst (follicle) is suspected, nothing need be done. A simple transvaginal sonogram performed a few weeks later will confirm that the “cyst” has resolved.
When a “cyst” is found, one can never be absolutely certain of the diagnosis. The only question that must be answered by the gynecologist is: “Is there reason enough to suspect that this cyst might be a benign tumor or malignancy?” If so, surgical intervention is indicated. The gynecologist should have good reasons (based on age, symptoms, concurrent medications, sonographic appearance, cycle day, change in appearance during serial sonograms, and other factors) to recommend surgery.
“Cysts” in Postmenopausal Women
Since postmenopausal women no longer ovulate, “functional” cysts should not occur. This is why gynecologists are much more concerned about “cysts” found in postmenopausal women than their premenopausal counterparts. These “cysts” are much more likely to be benign or malignant tumors that require surgical intervention. Once discovered, they are usually removed surgically or reexamined by transvaginal sonogram a few weeks later, depending on many factors.
Regardless, the vast majority of ovarian “cysts” discovered during routine pelvic exam or sonogram do not require surgery.