http://www.mjbovo.com/OvarianCysts.htm The most common site of a pelvic mass is the ovary. The age of the woman gives the doctor great insight into how serious the finding of an ovarian cyst can be.
Finding a cyst in a young girl before she's begun menstruation is alarming and can be malignant 50% of the time. An ovarian cyst in a post-menopausal woman is also frequently malignant. In both of these age groups, diagnostic surgery to make an absolute identification is needed. This can be done by either diagnostic laparoscopy which is inserting a tube with a camera attached to it through the belly button, or diagnostic laparotomy which is making an incision through the abdomen, and looking at the ovary.
The most challenging area of patient care for a doctor are the cysts that occur between these two extremes in the reproductive life of women. A sonogram can help in the diagnosis.
The most common cysts found are the functional cysts. A functional cyst can be one of four types and are not malignant: follicular, corpus luteum, theca luteum, and polycystic ovaries.
A follicular cyst occurs when the normal follicle, or sac that matured to release an egg, does not shrink after release of the egg. These are soft, have thin membrane walls, and contain clear fluid. These can rupture, causing sudden, severe pain which gradually goes away over several days. Usually, however, they spontaneously disappear over the course of one or more menstrual cycles. They can cause changes in your periods and pelvic pain. Depending on the size of the cyst, it can just be observed or treated with birth control pills.
Corpus luteum cysts are less common, but cause more symptoms and problems. They become larger than follicular cysts, thus causing more pelvic pain. They result when bleeding occurs in the follicle after an egg is released. This type of cyst often causes a delayed period and if it ruptures, can cause bleeding into the abdomen which may neccesitate surgery.
Theca luteum cysts, the least common of the functional cycts, are often asscociated with an abnormal pregnancy. They most often occur in both ovaries, unlike the functional cycts described above. They disappear without treatment after the pregnancy is terminated.
Polycystic ovaries are multiple clear fluid filled cysts in both ovaries and are associated with menstrual problems and hormone imbalances.
Endometriosis can cause complex ovarian cysts or endometriomas, also commonly called chocolate cysts. Up to 60% of women with endometriosis have ovarian involvement.