Methylene blue painting of the peritoneum for the diagnosis of endometriosis - Eshre 2011.

For insiders the diagnosis of endometriosis seems well established. The public and recently  also contaminating the scientific debate ,however, is  fueled by correct but maliciously misleading “scientific” information. That this harmful to patients, emphasised by several recent emails by patients triggered this blog. This statement about misleading information needs explanation.

The gold standard for the diagnosis of endometriosis is and remains laparoscopy.

Provided the laparoscopist has the experience. The necessity of experience to recognize endometriosis was clearly shown for minimal lesions. It also was demonstrated that in the absence of experience too often a cystic corpus luteum erroneously is operated for cystic ovarian endometriosis. Also for deep endometriosis as we repeatedly discussed and demonstrated at congresses can be very hard to diagnose and is easily missed, especially the smaller lesions of the sigmoid and lesions remaining after incomplete previous surgery. Lesions remaining after a bowel resection (indeed very often the margins are not endometriosis free) are virtually inpossible to diagnose. Few surgeons will even attempt to do surgery, while neither MRI or ultrasound will provide a reliable diagnosis.

Microscopical confirmation is a useful research tool but clinically overvalued. Clinical mistakes indeed are rare for deep endometriosis except after surgery, when fibrosis can erroneously be mistaken as endometriosis (moreover often suggested by ultrasound). Also for cystic ovarian endometriosis or typical lesions microscopical confirmation of endometriosis is rarely useful.

Patients need to understand the mechanisms why misleading information so often contaminates the debate. Since repetitive I do not hesitate to call this maliciously misleading, although probably not intentionally.

Researchers want to have impact with their findings, since this ultimately will improve their citation index, their career while facilitating asking grants to continue their research. This attitude can turn sour, when it results in

Making at the end of the abstracts or in titles far reaching conclusions not substantiated by data eg “these data suggest a new method for the diagnosis of endometriosis”. We already pointed this out in the article “the elephant in the room”.

It can become malicious when these overstretched conclusions are made in order to rank up in searching engines.

For insiders this cause little harm since they can judge whether the findings could be developed in a useful diagnostic tool (practically with an over 90% sensitivity and specificity) or whether it merely is a nice observation like so many others.  For patients however, it risks to become harmful when creating false expectancies.

That  ‘congress presentations’, ie before peer review and publication, are picked up by the lay press reinforces these mechanisms.

The other mechanisms were already discussed in this website.

Drug use : Pharmaceutical industry invest in finding new drugs but obviously will stimulate drug use. This is especially true for endometriosis since no drug today cures endometriosis

Many stubbornly want to maintain the unifying concept that endometriosis is one disease instead of considering it 3 diseases with specific symptoms and prevalences. Underlying to this is the concept of the pelvic surgeon, versus those with limited or no surgical skills as most of those emphasizing medical therapy or IVF.

Besides laparoscopy we do not have today a simple non invasive method to diagnose endometriosis, and with all due respect to scientific colleagues thinking differently, I do not expect a simple non invasive test in the next many years.

Deep and cystic endometriosis : as discussed, there is little clinical need for a non invasive test unless it would be specific for these types of lesions.

the mid ninety’s we demonstrated that CA125 did fit the criteria as a diagnostic test for deep and cystic  endometriosis. Yet this never became popular since not really helping treatment

in the eighties we published prolactin essays during surgery to differenciate between  cystic ovarian endometriosis and a corpus luteum. The test was never developed.

In order to avoid misunderstanding diagnosis remains based upon symptoms, clinical exam, ultrasound, MRI etc . Any test should have added value and do no harm : indeed if clinical decision would be based upon a test with 80% sensitivity and 80% specificity this would result in 1/5 woman undergoing surgery without being necessary, and 1/5 having no surgery although necessary.

typical and subtle lesions.

Peritoneal painting has been suggested several times and was proven not to be useful. The recent report on methylene blue is scientifically nice when discussing mesothelial cell damage (as discussed in adhesion formation) but is not expected to have clinical value for the diagnosis of endometriosis.

Narrow band imaging was suggested several times after introduction, but dismissed thereafter (emphasizing the misleading mechanism of information)

“Markers” in blood,  in menstrual blood or in endometrial biopsies today have no value. Many differences ( more than 150 papers) have been described between women with and without endometriosis (again by and large ignoring the different types)  but none of these data even come close to be considered a clinically useful marker. (also not for deep or cystic endometriosis). One of the last candidates ‘nerve density in the endometrium’ is another example of overstretched conclusions.

A key difficulty remains the absence of an animal model. I initiated the baboon project in Kenia, but realized that it was not a useful model since deep and cystic endometriosis could not be induced. Very recently a strange shadow came over the results since in the PhD at UCL,( Squifflet and Donnez) retrograde menstruation was not confirmed.

In conclusion today the search for simple non invasive diagnostic markers did not have any clinically useful results and I do not expect any results in the near future. A lot of good scientific work, for the reasons explained, do create false expectations for patients. In the absence of a clear conclusion that today there is nothing useful, information on diagnostic markers is generally misleading, sometimes even some malicious undertone can be suspected, in their notwithstanding clinically not useful rather positive conclusions.   


Philippe R. Koninckx and Anastasia Ussia 

Leuven and Gruppo Italo Belga, Rome Italy

Share This

Shiny Trinket

Shiny trinkets are shiny.