The disease
The main symptoms
The main symptoms of endometriosis include pelvic pain, dysmenorrhea, dyspareunia, dyschezia, and dysuria.
However, endometriosis is asymptomatic in 20–25% of cases.
The stage of the disease does not always correlate consistently with the frequency and severity of symptoms. Small lesions may be associated with more severe symptoms, while in some cases large lesions may result in minimal symptoms.
Typically pain begins before menstruation, gradually increases with the onset of menstrual flow, and tends to decrease as the flow subsides. However, it may also be chronic and debilitating and it can be accompanied by lower back pain and sciatica. Cramp-like characteristics are rare. Approximately 20% of patients experience pelvic pain of varying intensity, which may occur at any point during the cycle.
Nodular thickening due to deep infiltration in specific anatomical areas, such as retrocervix, uterosacral ligaments, parametrium, Douglas peritoneum or the intestinal wall, may cause fixation of pelvic organs with pain during sexual activity (deep dyspareunia) and a consequent negative impact on the patient’s quality of life.
During the menstrual period, additional symptoms, such as dysuria and hematuria, may occur.
Pain may also arise in the ureteral areas due to compressive phenomena. In case of obstructive lesions, renal function can be compromised, leading to hydronephrosis.
In case of intestinal involvement, bleeding is rare as the lesion typically infiltrates the muscular layer of the intestinal wall from the outside in, with the mucosa rarely being affected (5% of cases).
However, dysfunctional phenomena, such as diarrhea or constipation, are common. In case of significant intestinal stenosis, episodes of sub-occlusion or, more rarely, complete obstruction may occur. Defecation can be particularly painful (dyschezia), especially when endometriotic lesions are present in the most caudal part of the rectum and the rectovaginal septum.
Aside from the characteristic pain-related symptoms of endometriosis, another crucial aspect to consider is its correlation with infertility.
The precise pathophysiological mechanism underlying this association remains partly unclear, although several factors are likely involved. In the most severe and extensive form of the disease, infertility may be due to the presence of tenacious adhesions involving the tubal fimbriae, the Douglas pouch, and the ovaries, compromising normal anatomical relationships. Even if tubal patency is often preserved, the processes of oocyte release, capture, and transport are severely impaired.
Reduced fertility has also been observed in cases of mild or moderate endometriosis, with possible causes including altered prostaglandin secretion, changes in the peritoneal microenvironment affecting ovum-sperm interaction, and abnormalities in endometrial receptivity.
In general, the abdominopelvic inflammatory condition caused by endometriotic disease, regardless of localization, is associated with infertility.
Symptoms
Symptoms of endometriosis may include:
Pain intensity is commonly assessed using a Visual Analog Scale (VAS) score, ranging from 0 to 10. In 20%–25% of cases, however, endometriosis is asymptomatic, and the diagnosis is made incidentally during a surgical procedure performed for other reasons.
The stage of the disease does not always correlate consistently with the frequency and severity of symptoms. Small lesions may cause significant pain, while large lesions may produce only mild symptoms. Pain typically begins before menstruation, increases with the onset of menstrual flow, and decreases as the bleeding ends. However it can also be chronic and debilitating, often accompanied by lower back pain and sciatica.
It is rarely cramp-like. About 20% of patients report pelvic pain of varying intensity, which can occur at any time during the cycle. Nodular thickening of the uterosacral ligaments and the involvement, more or less extensive, of the pelvic peritoneum and the Douglas pouch lead to fixation of the intrapelvic organs.
Movement of the cervical canal during sexual activity may provoke intense pain (deep dyspareunia), to the extent that it may render intercourse incomplete or significantly reduce its quality.
During menstruation, other possible symptoms include dysuria and hematuria. Ureteral pain may occur due to compressive effects, and, in the presence of clearly obstructive lesions, full hydronephrosis may develop.
In cases of intestinal involvement, bleeding is rare because the lesion infiltrates the intestinal wall from the outside inward and the mucosa is almost never involved. However, dysfunctions such as diarrhea and constipation due to obstructive and stenotic lesions are frequent. Defecation may be particularly painful (dyschezia) when endometriotic lesions are located in the most distal part of the rectum and the rectovaginal septum. In addition to the characteristic pain symptoms of endometriosis, another fundamental aspect of this condition must be considered: its correlation with infertility.
The precise pathophysiological mechanism underlying this association remains partly unclear, although several factors are likely involved. In the most severe and extensive form of the disease, infertility may be due to the presence of tenacious adhesions involving the tubal fimbriae, the Douglas pouch, and the ovaries, compromising normal anatomical relationships. Even if tubal patency is often preserved, the processes of oocyte release, capture, and transport are severely impaired.
Reduced fertility has also been observed in cases of mild or moderate endometriosis, with possible causes including altered prostaglandin secretion, changes in the peritoneal microenvironment affecting ovum-sperm interaction, and abnormalities in endometrial receptivity.
Diagnosis
Anamnesis and Clinical Examination
This includes identifying clinical elements useful for guiding the subsequent diagnostic (laboratory/instrumental) and therapeutic phases. This step is fundamental to assess presence, nature an intensity of the patient’s symptoms and the impact that the pathology may have on her physical and psychological well-being. Key symptoms of endometriosis to be assessed include pelvic pain (dysmenorrhea, possibly associated with menorrhagia, dyspareunia, dyschezia and disuria), and infertility.
Serum Markers
However, it has been excluded as a reliable diagnostic test in the latest ESHRE guidelines.
Imaging Techniques (by experienced operator)
In our Center, the diagnosis is almost exclusively made through ultrasound performed by a specialist, with experience in over 15,000 cases and data of extremely high accuracy, validated by scientific studies published in leading international journals.
When transvaginal ultrasound cannot be performed, the same examination can be done via transrectal approach, with comparable reliability. Transabdominal ultrasound is always paired with transvaginal or transrectal assessment but is not sufficient alone, especially for evaluating deep infiltrating endometriosis.
Ultrasound, when performed by expert operators, allows extremely accurate staging of the disease, enabling precise identification and measurement of individual lesions in all pelvic and abdominal sites potentially affected — not only the internal genital system (uterus/adnexa), but also the urinary tract, intestines, all adjacent anatomical spaces (including nerve involvement) and even atypical sites, such as the diaphragm or abdominal wall.
MRI accuracy is comparable to ultrasound only when performed by skilled radiologists with sufficient experience in assessing the anatomical sites mentioned above.
A correct diagnosis via imaging, with a real “mapping” of the lesions, allows appropriate management decisions for patients with endometriosis. It also helps predict the complexity of any surgical procedure. This method allows for precise planning of the surgical strategy, providing the patient with detailed information and comprehensive counseling about the risks and benefits before entering the operating room.
Other radiological and endoscopic methods, such as double-contrast barium enema, intravenous urography, or uro-CT/uro-MRI, can be valid support tools in specific circumstances.
Regarding colonoscopy, it is not a preferred method for evaluating bowel endometriosis, since in most cases infiltrating nodules do not reach the intestinal mucosa (which is the inner layer best visualized by colonoscopy). Even in rare cases of mucosal involvement, colonoscopy only allows partial visualization of the nodule and does not provide information on depth or extent, which are crucial for treatment planning.
Therefore, colonoscopy is used only in doubtful cases where a differential diagnosis with malignant intestinal diseases is needed.
Some studies have assessed the diagnostic accuracy of double-contrast barium enema and colonoscopy for intestinal endometriosis. While the barium enema shows good accuracy in detecting stenosing lesions, it does not exceed the accuracy of transvaginal ultrasound, since it cannot assess infiltration depth precisely. Colonoscopy is not useful because most lesions do not affect the intestinal mucosa. Therefore, it is only indicated in uncertain cases needing differential diagnosis with gastrointestinal malignancies. In cases of posterior compartment endometriosis with suspected ureteral involvement and possible hydronephrosis, intravenous urography and contrast-enhanced uro-CT are valuable preoperative techniques for accurate evaluation of renal parenchyma and excretory pathways.
Staging
The classification system currently used by the Italian National Health Service (SSN) is the one adopted by the American Fertility Society (rAFS classification), which distinguishes 4 stages of the disease (I minimal, II mild, III moderate, and IV severe). This classification system presents significant limitations, primarily due to its reliance on surgical nature of the staging – it requires operative evaluation, i.e., a surgical procedure and thus cannot be applied based solely on diagnostic imaging. Furthermore, it does not account for cases of deep infiltrating endometriosis, rendering many advanced forms of the disease “unclassifiable” within this framework.
In light of these considerations, our Center uses, for surgical classification, both the aforementioned rAFS and the NEW CLASSIFICATIONS (Ultrasound and Surgical):
- #Enzian Score
- AAGL 2021 Classification
These new systems allow the disease to be staged using either ultrasound or surgical findings. They are primarily adopted in International Reference Centers and allow for more effective correlation with the disease’s severity and the difficulty of a potential surgical procedure.
When referring to infertility in a couple, we mean the inability to achieve conception after one year of unprotected sexual intercourse. Approximately 40% of patients with endometriosis may experience reproductive problems, depending on various factors: in the case of ovarian endometriosis, a reduced ovulation rate of the affected ovary is often recorded; in severe pelvic endometriosis, infiltrating lesions and associated adhesions may lead to anatomical/mechanical alterations, impairing tubal transport function. At times, the uterine environment may also be more hostile to embryo implantation. Even in cases of minimal endometriosis, there are inflammatory factors that may possibly hinder conception.
Moreover, it should be considered that a crucial parameter for a woman’s reproductive potential is age. Starting from the age of 35, the percentage of chromosomally abnormal oocytes progressively increases, leading to a greater risk of failed conception or early spontaneous miscarriages, regardless of the anatomical condition. Proper surgery for endometriosis, by restoring normal pelvic anatomy and removing lesions, thus reducing the pelvic inflammatory condition, can increase the chances of conception. However, this outcome is strongly influenced by the patient’s age and by the characteristics of the partner’s semen. Certainly, the highest conception rates after surgery are recorded for women under the age of 35.
Therefore, the decision to perform surgery with the sole purpose of restoring reproductive potential must be carefully evaluated and only after a proper assessment of the couple’s characteristics. It should also be considered that there is a possibility of reduced follicular reserve after ovarian surgery. The parameter of follicular reserve, which naturally decreases with age and can greatly vary from patient to patient, is crucial both for spontaneous conception and for assisted reproduction procedures.
For these reasons, proper counseling is always provided to the couple, ensuring they choose the most appropriate treatment method (surgery or assisted reproduction technique), always considering the value of the Anti-Müllerian Hormone (AMH) and the possibility of prophylactic Oocyte Cryopreservation.
On the other hand, it should be considered that, although pregnancy is often regarded as a “natural therapy” for endometriosis, in some cases, as reported in scientific literature, abnormal behavior of lesions (decidualization) may be observed during pregnancy (with an increased risk of complications during pregnancy and/or at delivery). This aspect must be discussed with the couple during the decision phase regarding the therapeutic strategy to be adopted – whether to consider surgical treatment even before pursuing assisted reproduction. Finally, it is essential that the patient understands how, at times, the disease can cause irreversible damage to one or both fallopian tubes. Often, when associated with clear dilation of the tubes, this is already recognized during the preoperative diagnostic phase. However, it may be detected only during surgery. It has been shown that clear anatomical damage to one or both tubes not only renders them inefficient for spontaneous conception but also potentially harmful in assisted reproduction, reducing the chances of success by up to 50%. Since reconstructive/restorative procedures are not always effective, it is mandatory to request, during the Informed Consent process, the patient’s agreement to the possible surgical removal of one or both tubes (Salpingectomy) if they are found to be “irreversibly compromised.”