Endometriosis is defined as the presence of endometrium-like tissue, i.e. the uterine lining, outside the uterus. In the vast majority of cases endometriotic tissue (lesions) are found in the abdomen, in particular in the pelvis of women. Only rarely endometriosis is found in other areas of the body. The abdominal lesions can be singular or multiple, have different colours (mostly red, clear, brown, black/blue or white), and lie superficially or invade deeper tissues or surrounding organs. Currently most people assume that three different types of abdominal endometriosis exist:
- Peritoneal endometriosis (i.e. superficial deposits on the lining of the abdominal wall)
- Ovarian endometriotic cysts (also known as endometriomas or ‘chocolate cysts’)
- Deep infiltrating endometriosis (i.e. nodular disease, infiltrating surrounding tissue).
How can endometriosis be diagnosed?
A) Medical History: Generally, as doctors and nurses we have various tools to diagnose a condition. Studies have shown that women with endometriosis often suffer from certain signs and symptoms. These include:
- Dysmenorrhea (painful periods)
- Dyspareunia (pain during sexual intercourse)
- Dysuria (pain when emptying the bladder)
- Dyschezia (pain when emptying the bowels)
- Non-cyclical abdominal pain
- Chronic fatigue
When endometriosis is present outside the abdomen symptoms such as cyclical pain in that particular area, repeated spontaneous pneumothoraxes (rupture of the lung membranes), cyclical bleeding from orifices can occur. However, these symptoms are extremely rare.
Unfortunately, none of the above named symptoms are exclusive for endometriosis and can be associated with other conditions. A large retrospective study demonstrated, though, that the more of these symptoms are present the more likely it is that a woman has endometriosis.
B) Examination: As a routine part of a clinical visit your doctor may decide to perform an internal examination. This may consist of a speculum examination of your vagina and cervix plus a digital examination of the vagina and possibly the back passage. Although some studies suggest that the findings are not very specific and their interpretation may be dependent on the experience of the doctor, it sometimes is possible to identify endometriosis involving the vagina and/or large bowel.
C) Imaging: Abdominal endometriosis might be detected using imaging modalities such as abdominal and/or vaginal ultrasound or magnetic resonance imaging (MRI). These approaches have been shown to be helpful in detecting ovarian endometriotic cysts and deep infiltrating disease especially involving the space between the vagina and the large bowel. However, even MRI can easily miss lesions on the peritoneum.
D) Biomarkers: Ideally, a blood, urine or saliva test should be available to help your doctor diagnose or exclude endometriosis, give an idea about the best treatment and possibly identify women who need additional treatment. Our group has a strong interest in such biomarkers. We recently performed two systematic reviews investigating the current state of such potentially existing molecules (Link to PDFs). Although we were able to identify more than 100 putative markers none of them were currently suitable for clinical use (SLIDE Biomarkers). Therefore, some of our current studies focus on identifying such markers or panels of markers (Link Research Studies).
E) Surgery: Endometriosis is a mostly intra-abdominal disease and lesions can be identified during surgery. Today, surgery should generally consist of a laparoscopy (‘key hole surgery”) as opposed to an open (laparotomy) procedure due to better vision and faster post-operative recovery. If endometriosis is identified then the recommendation in the current guidelines is ideally the histological verification of the disease. However, if no endometriosis can be identified under the microscope the condition is not fully ruled out.
In conclusion, laparoscopy remains the gold standard to diagnosis (Link Treatment). However, surgery does not necessarily need to be performed just to have a diagnosis. Your doctor may decide to perform ‘empirical therapy’ i.e. medical treatment assuming the presence of endometriosis. If your symptoms improve significantly and you are not suffering from strong side-effect, you may choose to stay on this treatment for some time.