Ovarian cysts are so common that almost every woman will have at least one during her reproductive years. When we hear the word “cyst,” many of us think of cancer, but most ovarian cysts are harmless and many don’t even need treatment.
The most common types of benign (noncancerous) ovarian cysts are functional cysts, so called because they develop as an occasional “side effect” of normal ovarian function. These cysts are responsible for enlarged ovaries in the majority of cases.
It’s not uncommon for a functional cyst to produce no symptoms; it may be discovered for the first time during a pelvic exam. A small number of patients with functional ovarian cysts, on the other hand, may have severe pain that requires them to be hospitalized for observation. Internal bleeding can occur. In rare cases, surgery might be necessary to stop the bleeding.
Although ovarian cysts often disappear on their own, in some cases a doctor might recommend one or two months on hormone pills to suppress the natural menstrual cycle. If you have a functional cyst that doesn’t shrink with hormone therapy, or if you’re older than 40, have severe pain or have a mass that’s larger than two inches, your physician will want to determine exactly what kind of cyst or tumor you have. He or she may recommend laboratory and imaging tests or laparoscopy.
There are two types of functional cysts: follicle cysts and corpus luteum cysts. Follicle cysts develop from ovarian follicles (tiny sacs in which eggs develop). A woman’s menstrual cycle begins each month when several ovarian follicles begin to grow. The follicles mature for about a week until one grows larger than the others and becomes the single, mature egg to be released from the ovary during ovulation. If ovulation doesn’t occur, this follicle may become a cyst. Filled with fluid, a follicle cyst generally causes little pain, requires no treatment and is reabsorbed into the ovarian tissue within one to two months.
A corpus luteum cyst is another type of benign ovarian cyst. These cysts occur more commonly than follicle cysts. Following ovulation, the egg is transformed into a cell mass called the corpus luteum.
Like the follicle, the corpus luteum may become filled with fluid and form an ovarian cyst. Symptoms of a corpus luteum cyst include a slight delay in menstruation, irregular or scant bleeding and pain on one side of the abdomen. Because these symptoms might indicate a tubal (ectopic) pregnancy, your physician may recommend ultrasound or laparoscopy to confirm the diagnosis.