"Ask Dr. Cook" is a series of questions and answers regarding endometriosis. The current subject and answer can be found on Current Ask Dr. Cook web page. The questions may represent a summary of questions I have been asked by several different patients. I hope you find this information helpful. If you have a question you would like answered, please Submit A Question.

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 as the one that was on my left ovary that my doctor removed during surgery three weeks ago. It is 5cm big, and what worries me is that it wasn't there during surgery three weeks ago. My doctor thinks it might me an endometrioma. Can you tell me more about ovarian cysts.

Answer:
If this cyst was not present three weeks ago, the chances of this being an endometrioma is almost zero. 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 which can be mistaken for ovarian cysts include paratubal cysts (not uncommon, usually not harmful), hydosalpinx (water in blocked tubes) and peritoneal inclusion cysts (cystic pockets of the inside lining of the body).

FUNCTIONAL CYSTS
Functional cysts include the developing follicular cyst, the hemorrhagic corpus luteum cyst and the unrupture 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 the egg sac, including the egg, the support cells and the surrounding fluid. Normally these cysts enlarge to about one inch. The egg is then released during ovulation and the cystic fluid drains out of the ovary and thus 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 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 cyst. This type of cyst can get pretty big and has an appearance similar to an endometrioma. A hemorrhagic corpus luteum cyst will appear suddenly and the body will reabsorb it over a month or two. The only way an endometrioma will disappear on a sonogram, other than surgery, is if it ruptures. Once in a while the developing egg is not released resulting in an unruptured follicular cyst. Ovulation does not occur. 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 (it is more difficult for the egg to escape from the ovary) and is probably more common the first month after pelvic surgery since the hormone production fluctuates with the stress of surgery. Some women are genetically predisposed to developing this type of cyst. Some physicians believe this is one cause of fertility and is called luteunized unruptured follicular (LUF) syndrome in women who repeated do not release the egg. The majority of the time follicular cysts will eventually resolve on their own.

ENDOMETRIOMAS
An endometrioma is a cyst in the ovary lined by endometriosis. As the endometriosis grows and sheds every month, the chocolate fluid accumulates and the cysts 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 (e.g. dog jumping on your lap or intercourse) the endometrioma can rupture and the contents 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 which is irreversible. Lupron does not treat endometriomas. If endometriomas are drained surgically they will recur. The surgeon must remove the entire lining of the endometrioma to eliminate the chance of that endometrioma 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 and it is only a matter of time before it fills back up.

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, if you have a cyst that is present 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.

Updatede October 29, 2005