This is a type of cyst caused by endometriosis on the ovary. They are often know as “chocolate cysts” because they contain brown liquid inside of them that resemble chocolate syrup.

It’s typically never “just an endometrioma”.

Multiple studies have shown that ovarian endometriomas are often an indication that the person also has more severe pelvic and intestinal endometriosis. If your doctor says that you “just have an endometrioma”, you may want to seek a second opinion with an expert excision surgeon. This way you get all of your endometriosis excised at once, without endometriosis being missed or you needing to reoperate for it.

Endometriomas need to be excised by an expert.

Endometriomas are best treated by excision surgery. Medical treatment (Lupron, Orilissa, birth control) doesn’t shrink them and they don’t resolve on their own.

Sometimes it can appear that an endometrioma is “shrinking” when follow up ultrasounds are done. However, this reduction in size is likely due to a change in density of the endometrioma components or a slow leakage of the chocolate fluid out of the endometrioma into the pelvis. Various studies have shown that endometriomas are rarely found by themselves, so typically a person with an endometrioma has more areas of endometriosis, so an endometrioma having a slight decease in volume doesn’t change the rest of your lesions or their severity.

Although there are many parts of the endometriosis guidelines I don’t agree with, both the 2022 European endometriosis guidelines as well as ACOG guidelines do say that they recommend excision of the endometrioma over drainage and ablation. However, unfortunately some general gynecologists lacking the excision skills necessary are still draining and ablating endometriomas.

Depending on the size and the endometrioma itself, it can be stuck to the rectum, ureters, the uterus, the other ovary, etc. It can take an hour or more to remove the endometrioma, and then the rest of the surgery has to begin! For all of these reasons, endometriomas, like all endometriosis, is best treated by an expert excision surgeon.

Endometriomas have a higher recurrence rate.

Endometriomas have a higher risk of recurrence than other types of endometriosis, even in the hands of an expert. And when they are not excised, the rate of persistence (endometriosis remaining because it was never properly removed in the first place) is even higher.

However, it’s important to know that if your endometrioma recurs, this doesn’t mean that your endometriosis in other areas has also recurred.

Taking hormonal suppression doesn’t prevent endometriosis from recurring.

Although some doctors insist that the patient go on hormonal suppression after surgery to prevent recurrence, various studies following patients using post surgery hormonal suppression (PSHS) have shown that people using PSHS can still have endometriosis recurrence.

Likewise, various data worldwide have shown that endometriosis recurrence rates are low in the hands of an expert. Endometriosis only recurs in 7-20% of people, (depends on person, surgeon skill, surgeon training, persistence vs recurrence, etc) and that recurrence is not dependent on using or not using PSHS. Various studies have shown that patients who had an excision and did not use PSHS were operated on some years later and no endometriosis recurrence was found.

  • It’s possible to have excision, take PSHS, and have recurrence even though you are on hormonal suppression.
  • It’s also possible to have excision, not take PSHS, and have no recurrence (which shows that people don’t need to take PSHS to have no endometriosis recurrence).

Now, while postoperative medical treatment doesn’t prevent recurrence, some studies done on endometriomas suggest that taking hormones post operatively can sometimes help to slow potential endometrioma recurrence for some people (note I’m speaking here about endometrioma recurrence, and not recurrence of superficial or deeply infiltrating endometriosis). But not all studies show the same results on PSHS either – some found that PSHS doesn’t appear to play a significant role on postoperative endometrioma recurrence rates. When looking at studies, it’s important to know that studies can have different limitations and methodologies. Some studies define endometriosis recurrence as visualization of an endometrioma on an ultrasound (this would be actual disease recurrence), while others define recurrence as the return of pain symptoms without actual visual or histological proof of endometriosis, which is quite different because symptoms can return post-operatively due to other pain generators without endometriosis lesions itself actually recurring. In studies, it’s also hard to know if complete or incomplete excision was done during the surgeries – so it is actually recurrence or is it persistence? 

Taking hormonal suppression after surgery is an individual choice, not a requirement. Some benefits may be that you want a form of birth control, or that when you take hormones, they help manage your adenomyosis symptoms. However, don’t feel like you have to take hormones to prevent endometriomas or endometriosis recurrence because you don’t, and there is no solid proof based on good research that hormonal suppression does this. Some doctors really insist the patient take PSHS to “prevent recurrence” and therefore some patients take hormones even though they don’t want to, or even though the hormones cause them upsetting side effects, because they feel like they need to in order to prevent endometriosis recurrence. But this isn’t true because endometriomas and other types of endometriosis can recur even when a person takes PSHS – and we do have solid proof of this.

Another thing to keep in mind if you decide to use PSHS is that there is no magic hormone, in spite of what some doctors may believe. The aim of postoperative medical treatment is suppressing ovarian activity, and this can be done via oral contraceptive pills, rather than GnRh drugs like Lupron and Orilissa. In fact, oral contraceptive pills have a much lower side effect profile than GnRh drugs do, and you can be on oral contraceptive pills for much longer. 

So be wary of any doctor telling you that you have to use PSHS to prevent or delay recurrence, or of any doctor telling you that you have to use a specific hormone. It’s your choice if you use hormones and in that case, what hormones you use.

Here’s a good quote to reiterate this:  “Although the scientific community is trying to find an algorithm of treatment for endometriosis that can be universally applied, to date, there is no ideal drug that can prevent, inhibit, or stop the development of endometriosis. Almost all of the currently available treatment options for endometriosis suppress ovarian function and are not curative.” (A.A. Gheorghisan-Galateanu 2019)

For more resources