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Ovarian Cysts

Question:

I had a CT scan done, and it turns out I have a huge cyst on my right ovary. It appears to be the same size as the one that was on my left ovary, which my doctor removed during surgery three weeks ago. It is 5cm big, and what worries me is that it wasn't there during that surgery. My doctor thinks it might be an endometrioma. Can you tell me more about ovarian cysts?

Answer:

If this cyst was not present three weeks ago, the chance of it being an endometrioma is almost zero. Endometriomas take time to grow, usually months to years. Let's review the basic types of ovarian cysts (not including pregnancy cysts): These include (1) functional cysts, (2) endometriomas, (3) benign ovarian cystic tumors, and (4) malignant ovarian tumors. Other structures that can be mistaken for ovarian cysts include paratubal cysts (a water-filled cyst next to the fallopian tube; these are not uncommon, and usually are not harmful), hydosalpinx (water in blocked tubes), and peritoneal inclusion cysts (cystic pockets of the inside lining of the body, which are rarely harmful).

Functional Cysts
Functional cysts include the developing follicular cyst, the hemorrhagic corpus luteum cyst, and the unruptured follicular cyst (also called a simple cyst). The developing follicular cyst is found in the ovary during the first two weeks of the menstrual cycle. This is actually the egg sac, and includes the egg, the support cells, and the surrounding fluid. Normally, these cysts enlarge to about one inch. When the egg is released during ovulation, the cystic fluid drains out of the ovary, and the cyst goes away. This cycle of events happens almost every month in a woman with normal menstrual cycles. These cysts rarely cause pain, unless the ovary is surrounded by adhesions (scar tissue).

A hemorrhagic corpus luteum (HCL) cyst forms when the egg breaks a small blood vessel in the ovary during ovulation. The broken blood vessel can bleed into the ovary and develop a blood clot, or what is medically called a hemorrhagic corpus luteum (HCL) cyst. This type of cyst can get pretty big, and has an appearance similar to an endometrioma. A HCL cyst will appear suddenly, but the body will reabsorb it over a month or two, just like a big bruise. If your doctor is not sure if the cyst is an endometrioma or a HCL cyst, he or she may repeat a sonogram in a month or two. The HCL cyst will disappear, while the endometrioma will not go away.

Once in a while the developing egg is not released, resulting in an unruptured follicular cyst. In this case, ovulation does not take place. This condition probably occurs in most women once in a blue moon (the second full moon occurring in the same month). Unruptured follicular cysts occur more often when the ovary is surrounded by adhesions (since it is more difficult for the egg to escape from the ovary).

Some women are genetically predisposed to developing unruptured follicular cysts. Physicians refer to this as luteunized unruptured follicular (LUF) syndrome, and believe that the inability to release an egg from an ovary caused by LUF can be a cause of infertility in women. Most of the time, follicular cysts eventually resolve themselves on their own.

Endometriomas
An endometrioma is a cyst in the ovary; it is lined by endometriosis. As the endometriosis grows and sheds every month, it bleeds into the ovary and "chocolate fluid" accumulates, and the cyst grows. This type of cyst can be devastating to a woman's reproductive function. If left to grow, it will tend to progressively destroy normal ovarian tissue. If it gets large enough, or if trauma occurs (by the dog jumping on your lap, or through intercourse or other actions), the endometrioma can rupture and its contents will spill into the pelvic cavity. The chocolate contents are very irritating to the body and can result in extensive adhesion formation, including damage to the fallopian tubes. This damage is irreversible.

If endometriomas are only drained, they will recur. The surgeon must remove the entire lining of the endometrioma to eliminate it from recurring (it is possible for a new one to form). If a surgeon coagulates or laser vaporizes the lining of the endometrioma, removal of the lining is usually incomplete. Then it is only a matter of time before it fills back up. Lupron does not treat endometriomas.

Benign Ovarian Tumors
There are many types of benign ovarian tumors, including dermoid cysts. Discussion of the various types of benign tumors is beyond the scope of this discussion. Suffice it to say that if you have a cyst on your ovary and it doesn't go away after a couple of months, it should be investigated.

Malignant Ovarian Tumors
Malignant ovarian tumors are cancer. These are more common in older women, but are found in all age groups, including teenagers. Some of you have heard that endometriosis can turn into cancer. It is possible, and I have seen a couple of cases in my career. But I would like to emphasize that this is very rare. The important point is not to ignore an abnormal finding.

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