Endometriosis

What is endometriosis?
Endometriosis is a condition in which endometrial – (tissue from the lining of the uterus) type tissue is found in areas outside of the uterus.
It is a common condition affecting at least 10% of women. The figure may well be as high as 50% but there is difficulty in getting a more accurate figure as it does not alway cause symptoms and, even when it does, the diagnosis is not always made.
Small deposits of endometriosis are scattered around the pelvis. There is no evidence of scarring.
The deposits of endometriosis are larger and more confluent through the pelvis and lower abdomen. There may be endometriomas and deposits on other pelvic structures. Scar tissue is not uncommon.
Most structures in the pelvis are affected. Significant scarring is often present such that they may obliterate the normal anatomy between the pelvic and abdominal structures.
Theories on how endometriosis occurs include:
- Retrograde menstruation: endometrial tissue is deposited in strange locations because of menstrual flow that backs up into the fallopian tubes and abdominal cavity.
- Ceolomic metaplasia: the areas lining the pelvic organs have certain cells that can grow into other forms of tissue such as endometrial cells.
- Surgery: endometrial tissues are directly transferred outside the uterus during episiotomy or Caesarean section.
- Blood and lymph systems: endometrial cells travel via the bloodstream or lymphatic system to other organs including the brain.
- Immune system problems: result in failure of the body to recognize and destroy cells or tissue that is growing where it should not be.
None of these theories have been proven
Types of endometriosis
- Small deposits of endometriosis less than 2mm in width.
- These deposits can be white, black, red, brown, yellow, bluish or clear in appearance.
- Are usually more than 2mm in diameter.
- These deposits can be white, black, red, brown, yellow, bluish or clear in appearance.
- They tend to extend more deeply into the tissue affected than do implants.
- Also known as ‘chocolate cysts.’
- Are ovarian cysts filled with old blood.
- Are of various sizes but can get to over 10cm in diameter.
- Endometrial-type tissue grows into the muscular layer of the uterus.
- Causes heavy, prolonged, painful menstrual periods.
Where are endometrial deposits found?
- Utero-sacral ligaments
- Pouch of Douglas
- Pelvic peritoneum
- Ovaries
- Fallopian tubes
- Uterus
- Rectum
- Abdominal peritoneum
- Large intestine
- Small intestine
- Appendix
- Bladder
Surface of the:
- Lungs
- Diaphragm
- Brain

Large nodule (blue-black) on lower left utero-sacral ligament. Larger infiltrative nodule on lower right utero-sacral ligament.

Distortion and scarring of Pouch of Douglas. Endometriosis over left ureter. Adhesions of right ovary. Early cyst left ovary.

Deposit and scarring right lower utero-sacral ligament. Involvement of peritoneum of both utero-sacral ligaments but not in Pouch of Douglas.

Right endometrioma. Adhesions of descending colon to right ovary and fallopian tube.

Endometriosis deposits on the peritoneum of the lower abdominal wall. Distortion results from scarring of the peritoneum.

Cystic endometriotic deposits in Pouch of Douglas and on peritoneum lateral to both utero-sacral ligaments.
- The classical “powder-burn” or blueberry lesion.
- White lesions that mimic scar tissue.
- Clear or slightly brown-colored papillary lesions.
Endometrial deposits have many appearances. This contributes to the diagnosis being missed by less experienced surgeons.
- Strawberry or flame-like lesions which are recently-developed and very hormonally active.
- Peritoneal pockets which most often contain endometrial implants.
- Deep culdesac nodules.
Symptoms of endometriosis
There is a poor correlation between the degree of endometriosis found visually and the symptoms reported by patients.
- Painful periods.
- Pelvic pain.
- Abdominal pain.
- Lower back pain.
- Pain whilst emptying the bladder.
- Pain during or after sex.
- Pain during bowel movements.
- Blood in the urine.
- Blood in bowel motions.
- Diarrhoea.
- Reduced fertility.
- Chronic fatigue.
Rarely, symptoms result from deposits of endometriosis in rare sites and may include:
- Haemoptysis (coughing up blood).
- Chest pain.
- Headache.
- Seizures.
Making the diagnosis
Treatment of endometriosis
Treatment may not be required for the majority of women who either do not have any symptoms or who have minimal symptoms.
The choice of treatment will be influenced by:
- The age of the woman.
- Her desire to become pregnant.
- How bad the symptoms are.
- The degree of endometriosis found during laparoscopy.
Treatment options include:
- Hormonal manipulation.
- Surgery
- Combined therapy.
Hormonal manipulation
- May reduce both heavy and painful periods associated with endometriosis.
- Are more effective if taken continuously – ideally 3 months in a row followed by a withdrawal bleed.
To be effective in symptom relief, administration needs to be continuous:
- Daily tablets.
- 3 monthly injections.
- Mirena IUCD.
- Oral therapy – Danazol.
- Injections – GnRH analogues.
Surgery is the definitive treatment for endometriosis. The aim is to destroy or excise endometriotic deposits, cysts and adhesions.
Laparoscopic management is the ‘gold’ standard as in most cases fertility is preserved and endometriotic deposits can be destroyed or resected.
Open surgery may be required for severe endometriosis, particularly if the ureters need to be re-implanted or bowel endometriosis resected.
Hysterectomy is considered to be end-stage treatment. It should be accompanied by resection or destruction of all visible endometriotic deposits.
Although the cause of endometriosis remains poorly understood, the driving factor for the activity of the deposits is oestrogen. Thus, menopause usually results in resolution, unless exogenous oestrogens are administered (i.e. HRT). Pregnancy is also a ‘pseudo hypo-oestrogenic state’ where the body behaves as if oestrogen levels are very low. Symptoms of endometriosis often improve during pregnancy, and in some cases do not recur afterwards.

- Endometriosis is most often diagnosed in women between the ages of 25-50.
- It can become symptomatic anytime after the menarche (1st menstrual period).
- Diagnosis is best established by visual diagnosis (laparoscopy) supported by biopsy .
- Hormonal therapy (reversible) and hysterectomy (irreversible) are contraindicated in women who wish to become pregnant.
- Treatment will often need to be multidisciplinary.