Endometriosis Part I: Evaluation and Diagnosis

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Be sure to check out our previous episode on chronic pelvic pain with Dr. Eva Reina to round out your CPP diagnosis skills!

What is endometriosis? 

  • Gynecologic condition where endometrial glands and stroma occur outside of the uterine cavity that can respond to hormonal shifts of the menstrual cycle.

    • Most within pelvis, but can occur elsewhere: bowel, diaphragm, and even in the pleural cavity 

    • Benign, but can cause dysmenorrhea, dyspareunia, chronic pain, and infertility 

  • Incidence

    • Occurs in 6-10% of reproductive age women, but is present in 38% of women with infertility and 71-87% of women with chronic pelvic pain! 

    • No data to suggest that endometriosis is increasing, but it is likely more recognized and being diagnosed more often now.

    • There is a familial association - first degree relatives of someone with endometriosis are at higher risk for also developing it, but the inheritance is likely polygenic-multifactorial 

  • Risk factors

    • Nulliparity, prolonged exposure to endogenous estrogen (ie. early menarche, late menopause)

    • Shorter menstrual cycles, heavy periods, obstruction of menstrual outflow

    • Increased height, lower BMI, and high consumption of trans unsaturated fats

      • This does not mean that you’re going to get endometriosis if you’re tall or have a low BMI! And you’re not going to treat it by stopping eating trans fats.

      • Association doesn’t equate to causation.

  • Etiology 

    • Endometriosis occurs when ectopic endometrial tissue implants, grows, and elicits inflammatory response 

    • Inflammatory response: COX-2 activity, overproduction of prostaglandins, and then chronic inflammation → triggers pain and causes infertility

      • Also why those with endometriosis will usually have flares that coincide with their menstrual cycle.

    • Nerve growth factor is also highly expressed in endometriotic lesions → increase density off nerve fibers → can explain increased sensitivity and pain 

      • Can also be explained by central sensitization (lowering threshold of pain) 

      • Go back go our CPP episode to remember what all these things are! 

    • Sampson’s Theory of Retrograde Menstruation - most popular/common theory where endometrial cells flow backwards through the fallopian tubes into the peritoneal cavity during menses

      • But, up to 90% of women HAVE retrograde menstruation, and not everyone has endometriosis 

      • Likely, there is a multifactorial cause of endometriosis, where ectopic endmoetrial tissue interacts with alterned immunity, imbalance of cell proliferation/apoptosis, aberrant signalling, and genetic factors 

      • There are certain genes that are statistically associated with endometriosis 

    • Chronic inflammation and endometriotic lesions can distort the pelvic anatomy through adhesions, endometriomas, and other substances lilke cytokines and prostaglandins that are “hostile” to normal ovarian function, fertilization, and implantation 

How do we evaluate for endometriosis? 

  • History and physical

    • Usually patient will present during reproductive years with pelvic pain (ie. dysmenorrhea or dyspareunia), infertility, or ovarian mass 

    • However, there are many people with endometriosis who are asymptomatic! 

    • Diagnosis is more likely to be made in people with symptoms 

      • Remember the “PPUBS” framework 

        • Pain - can you describe your pain? 

        • Periods - menstrual history; is the pain surrounding menstruation or line up with other parts of their menstrual cycle? 

        • Urinary symptoms - there can be endometriotic lesions on the bladder → frequency, urgency, pain with voiding 

        • Bowel - symptoms include diarrhea, constipation, dyschezia, and bowel cramping 

        • Sexual dysfunction - peritoneal or deeply infiltrating endometriosis can present with dyspareunia 

    • Physical exam: can be variable depending on location and size of implants

      • You may feel nodules in the posterior fornix, uterosacral ligaments,, adnexal masses, and immobility or lateral displacement of the cervix or uterus 

      • However, exam can be completely normal 

  • Rule out other causes for pelvic pain 

    • Labs - no pathognomonic lab for endometriosis 

      • CA125 can be elevated, but it’s not routinely ordered because other diseases can also elevate CA-125 levels 

      • It’s not specific and not helpful for endometriosis

    • Imaging 

      • Ultrasound is usually all you need - can see things like endometriomas, nodules, etc. 

      • Sometimes, can consider MRI

      • Imaging can help to rule out other causes of pelvic pain (ie. fibroids)  

  • Definitive diagnosis vs. presumptive diagnosis 

    • Presumptive diagnosis

      • Endometriosis is a pathologic diagnosis - meaning you need histology of a lesion biopsied during surgery 

      • Sometimes, if surgery is not desired or not yet possible, presumptive diagnosis can be made based on combination of signs, symptoms, and imaging findings 

      • Clinical diagnosis is enough to start therapy that is low risk and easily tolerated

      • If patients improve, can actually hold off on surgery 

    • Definitive diagnosis 

      • Surgery - usually indicated for persistent pelvic pain that does not respond to medical therapy, evaluation of severe symptoms that limit function, andd treatment of anatomic abnormalities 

      • Usually laparoscopy - can get definitive diagnosis and treatment 

        • Peritoneal lesions can appear like reddish or bluish irregularly shaped islands, “powder burn” lesions, white opacifications, translucent blebs

        • Allen-Masters syndrome = scarred or puckered peritoneal surface 

        • Dense fibrous disease 

        • Endometriomas 

    • Pathologic Categorizations 

      • Superficial peritoneal lesions 

      • Ovarian lesion (endometrioma) 

      • Deeply infiltrating - solid endometriosis situated more than 5 mm deep to the peritoneum 

    • Surgical Staging - this is to report operative findings. They do NOT correlate with presence or severity of symptoms. However, there are studies that have shown inverse correlation with advanced stages and prognosis for fertility treatment 

      • Stage I - minimal disease; ie. isolated implants, no significant adhesions 

      • Stage II - mild endometriosis with superficial implants that are < 5 cm in aggregate and are scattered on peritoneum and ovaries. NO significant adhesions 

      • Stage III - Moderate disease with multiple implants, both superficial and deeply invasive, peritubal and periovarian adhesions may be evidence  

      • Stage IV - severe disease; multiple superficial and deep implants, including large ovarian endometriomas. Filmy and dense adhesions are usually present