Endometriosis

“Endometriosis is a benign and chronic disease that is characterised by the growth of endometrial tissue outside the uterus, inducing a chronic, inflammatory reaction”

Risk Factors

• Female + age (most common is 20-40 yrs)
• Family history + genetics
• Nulliparity
• Retrograde menstruation (backflow of menstrual fluid containing endometrial cells)
• Previous pelvic inflammation or infection
• ­↑ Oestrogen levels
• Have periods longer than 7 days and cycles shorter than 28 days

Pathophysiology

The exact cause of endometriosis is unknown

• Retrograde menstruation:
  • During menstruation, endometrial tissue flows backwards → fallopian tubes → abdomen. In some cases, the tissue can then implant in the pelvis → endometriosis
• Hormonal:
  • ↑ Oestrogen production → encourages growth and shed of endometrial tissue
• Lymphatic or circulatory spread:
  • Endometrial tissue travel via the lymphatic system or in the bloodstream → implant in areas such as the lungs
• Metaplasia:
  • The substitution of one type of fully differentiated cell for another within a given tissue. 
  • Metaplasia usually occurs in response to inflammation to enables cells to better adapt to their environment.
  • Potentially explains how endometriosis appears spontaneously inside the body,
  • Potentially explains the appearance of endometriosis cells in women with no womb – or in men who have taken hormone treatments.
• Immune dysfunction:
  • The immune system may not able to fight off endometriosis.
  • Many women with endometriosis appear to have reduced immunity. It is not known whether this contributes to endometriosis or whether it is as a result of endometriosis.
• Toxin exposure:
  • Toxins, such as dioxin, can impact the immune and reproductive system
• Surgical:
  • Endometrial cells can move during a procedure such as a hysterectomy or c-section.
• Genetic:
  • There may be an inherited component. A woman with a close family member who has endometriosis is more likely to develop endometriosis herself.

Clinical Presentation

• Asymptomatic
• Infertility
• Fatigue
• Cyclical (pain and GIT symptoms)
• Dysmenorrhoea
• Dyspareunia
• Dyschesia
• Chronic pelvic pain
• Endometriosis can be seen in other locations such as the lungs, umbilicus and skin (cells react in the same way as to those in the pelvis)

Investigations

• Laparoscopy and histological verification is the gold standard
• Ultrasounds scan
• Pelvic examination
• A diagnosis can be categorised as follows:
  • Stage 1: Lesions are minimal and isolated
  • Stage 2: Lesions are mild. There may be several and adhesions are possible.
  • Stage 3: Lesions are moderate, deep or superficial with clear adhesions
  • Stage 4: Lesions are multiple and severe, superficial and deep, prominent adhesions

Management

• Around 1/3 patients find their symptoms resolve on their own, and recede with menopause
• Medical:
  • Non­hormonal
    • Simple analgesia (ibuprofen)
  • Hormonal
    • Progestogens
    • Combined oral contraceptive
    • Hormonal IUD
    • Gonadotrophin releasing hormone agonists +/­ add back HRT
• Surgical:
  • Conservative – aim to destroy all visible endometriosis
    • Diathermy
    • Excision
    • Laser
  • Radical – remove uterus, ovaries and nodules

Complications

• Up to 50% women present with infertility
• ­↑ Risk of ovarian cancer or endometriosis-associated adenocarcinoma
• Ovarian cysts
• Inflammation → chronic pain
• Scar tissue and adhesion development
• Intestinal and bladder complications