A system of classification or staging of endometriosis is useful in order to better describe the disease, develop better diagnostic modalities and treatments as well as to enhance research and standardize communication between scientists and health professionals.
Endometriosis appears in many different forms with a wide variety of clinical presentations depending on the extension of the disease, organs affected and individual circumstances. Therefore a unified consensus classification system for the stages of the disease is not a simple task.
The system is divided into four stages or grades according to the number of lesions and depth of infiltration: minimal stage (I), mild stage (II), moderate stage (III) and severe stage (IV). The system allows for a way to numerically scale the disease. A score of 15 or less indicates minimal or mild disease. A score of 16 or higher may indicate moderate or severe disease. As mentioned before, the severity or the score of the disease does not necessarily correlate to the level of pain or presence of other symptoms.
Key Terms Involved in the I–IV Staging System
The ASRM defines the following terms:
•Endometriosis implants: These are endometrial cells, which typically grow inside of the uterus, that grow and spread outside of the uterus. Endometrial lesions are generally small and flat.
•Endometrial adhesion’s: These are clusters of fibrous tissue that form in bands. Endometrial adhesion’s can bind organs together. Typically, those include the abdominal and pelvic organs.
•Ovarian endometriomas: Also known as chocolate cysts, these blood-filled cysts turn brown over time. The cysts grown on the ovaries endometrial cells spread and grow there.
•Filmy adhesion’s: Thin bands of scar tissue that form in response to the body’s attempts to protect itself from the inflammation caused by endometriosis.(They can also form because of the surgeries used to diagnose and treat it.)
Adhesion’s tend to make organs to stick together, which can cause sharp, stabbing pain, as well as other symptoms depending on their location. For example, when on the reproductive organs, adhesion’s can make it harder for someone to get pregnant. Adhesion’s on the bowel may lead to gastrointestinal symptoms, such as nausea.
Stage 1 Endometriosis
Stage 1, or “minimal” endometriosis, is used for cases that:
•Involve few small and superficial endometrial growths.
•Have growths on organs or the tissue that lines the pelvis and abdominal cavity.
•Show minimal or no scar tissue.
There a few small implants or small wounds or lesions. They may be found on your organs or the tissue lining your pelvis or abdomen. There’s little to no scar tissue.
Stage 2 Endometriosis
Stage 2 endometriosis defines “mild disease.”
•More implants than in stage 1
•Deeper implants than in stage 1
•Possible scar tissue, but no signs of active inflammation.
At this stage, there is evidence of: More implants than in stage 1. They’re also deeper in the tissue, and there may be some scar tissue.
Stage 3 Endometriosis
•Cysts (ovarian endometriosis) in at least one of the ovaries
•Filmy adhesion’s (in some cases)
•Many deep endometrial implants.
This is also known as moderate endometriosis. With stage III, deep implants are present. Also, adhesion’s may be dense instead of filmy and thin. As a result, endometriosis is more widespread than in Stage II.
Stage 4 Endometriosis
Stage 4 endometriosis is the most severe. At this stage, there are:
•A large number of cysts
This is also known as severe endometriosis. With stage IV, deep implants and dense adhesion’s are present. There may be superficial endometriosis and filmy adhesion’s, but the disease is more widespread than in Stage III.
While staging endometriosis is comparatively straightforward, diagnosing endometriosis in the first place can be challenging. This is partly because many common symptoms, such as pelvic and abdominal pain, can be caused by other health conditions,
Although endometriosis currently has no cure, therapies can help individuals manage their symptoms. Fertility specialists personalize their treatment plans for each patient. Treatments are generally the same regardless of the stage of the illness.