Endometriosis is a condition in which endometrial, or endometrial like tissue grows outside of the uterus. Although in the vast majority of cases the endometriosis is located within the pelvis (on the uterosacral ligaments, in the ovaries or on the pelvic wall) it can rarely been found in other locations such as the lungs, umbilicus and ski n.


  • A genetic link has been established for endometriosis. The origin of the lesions is mostly retrograde menstruation; however for some of the further afield lesions, such as lungs, spread is thought to be through blood or lymph.
  • Some books mention Sampson‚Äôs theory, which ties in patient age, with their obstetric and gynaecological histories and predicts various things like the site of the lesions, and the likelihood they will recur after surgery. It‚Äôs quite complex, but likens the endometrial tissues to dandelion seeds spreading throuought the pelvis.
  • There are also some autoimmune and environmental factors implicated.



  • Endometriosis is a relapsing/remitting condition.
  • The endometrial tissue acts just like it would in the uterus, responding to cyclical hormone levels, growing and bleeding at certain times of the cycle.
  • If the tissue is in the ovaries, then chocolate cysts form into which the lesions bleed.
  • Due to inflammation that happens at the site of the endometrial tissue, fibrosis occurs and in the abdomen and pelvis this leads to adhesions forming. These can lead to a frozen pelvis, and often affect fertility.
  • Very rarely these can be malignant.


Signsand Symptoms

  • Quite a lot of people with endometriosis are asymptomatic. However endometriosis is a common cause of chronic pelvic pain, and can also cause deep Dyspareunia, dysmenorrhoea and Subfertility. The obvious sign is bleeding from odd places, and indeed depending on the site of the lesion you can get haematuria, rectal bleeding, bleeding from the skin, or even in the eyes!
  • If a chocolate cyst ruptures, then you get signs of an acute abdomen, acute pain, tenderness, fever etc.
  • All of the symptoms tend to be cyclical in response to circulating hormones; however some may persist for periods.



  • Bloods for anaemia and hormone levels
  • Can do urine dipstick to confirm haematuria.
  • Laparoscopy, as diagnosis is made by actually seeing the lesions (plus or minus biopsy)
  • Transvaginal ultrasound to exclude cancerous causes (endometrial cancers) and to look for ovarian cysts.
  • MRI scans give such good resolution images they can often show previously undetected lesions.



  • If the endometriosis is asymptomatic then often no treatment is needed.
  • There is supportive treatment, analgesia for the pelvic pain.
  • Active treatment comes in two forms, medical or surgical
  • Medical is control of the bleeding, much as you would for menorrhagia (COCP, Progesterones, Intrauterine systems, GnRH analogues etc)
  • Surgical treatment can involve several procedures
    • Diathermy (laser or bipolar).
    • Dissection of the pelvic adhesions.
    • Last resort ‚Äď Total hysterectomy and bilateral salpingo-oophorectomy. (Can be done vaginally, abdominally or laprascopically)
    • Fertility help for if the woman wishes to conceive.

Useful Resources

Two good websites to have a quick look at. They both have good explanations if revising for explaining stations for OSCEs!


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