This is the presence of functioning endometrial tissue outside of the uterus
Generally, this is only discovered at laparoscopy so the true incidence is difficult to discover. Estimates range between 1-10% of women will have endometriosis during their reproductive years. Endometriosis regresses spotaneously or fails to progress in 50% of cases
To sum it up, they don't really know and for a variety of reasons.
Retrograde menstruation (endometrium pushed out of the Fallopian tubes during menstruation) is the best theory so far but has not been proven. It is mostly found on the ovaries, the uterosacral ligament and the pouch of Douglas, which favours this theory.
Ectopic endometrium (endometrium not in the normal place i.e. uterus) forms minature cysts which respond to cyclical secretion of oestrogen and progesterone. Cyst size depends on location with ovarian cysts (endometriomata) tending to be bigger. These cysts bleed during menstruation but the gunk that would normally leave via the vagina stays in the cyst. Eventually, they become big and full of brown blood.
Cysts can rupture resulting in multiple adhesions around the original cyst.
- Allergies - eczema, food, hayfever
- Exposure to pollutants - rare.
- Early menarche - rare.
The main features of endometriosis are:
- Pain - The pain is crampy and occurs in the lower abdomen. It starts premenstrually and and peaks a few days after menstruation. It is sometimes referred to as acquired dysmenorrhoea. Pain on defaecation can occur if the adhesions involve the peritoneum over the bowel.
- Menstrual disturbance - This occurs in 60% of women. Spotting premenstrually, heavy periods or increased frequency of periods are all possible symptoms of endometriosis.
- Dyspareunia - This is pain during sex and usually occurs with lesions in the pouch of Douglas (rectouterine pouch).
- Infertility - This is not strictly a symptom but endometriosis is often associated with it.
However, 25% are symptomless. Pelvic examination is often normal but larger cysts can be palpable as fixed, tender nodules.
Diagnosis of endometriosis is done laparoscopically. A biopsy of the lesion is taken during laparoscopy and visualisation of the lesions allows an assessment of the extent of the disease. In very severe disease, laparotomy is necessary for assessment and treatment.
Endometrial classification is split into 5 categories: minimal, mild, moderate, severe and very severe (I-IV respsectively). Essentially, this varies from small surface nodules (minimal) to lesions with scarring, ovarian endometriomata >2.5cm, lesions in the pouch of Douglas and involvement of other large organs e.g. bowel, bladder etc. (very severe).
This depends on the severity of the disease and on what works for the patient. Broadly speaking it can be split into drugs and surgery.
The mainstay of treatment are GnRH analogues, the Pill and progestogen preparations. Certain situations have been observed to reduce symptoms of endometriosis: pregnancy, menopause and androgenic situations. Each medication mimics one of these states.
GnRH analogues induce a menopausal state. Overstimulation of the pituitary causes a down-regulation of GnRH receptors in the gland. This results in a reduction in gonadotrophin production and hence ovarian hormone production.
It is given intranasally or via a long-acting injection for 3-6 months and its effects are similar to danazol. However, its adverse effects are hot flushes (almost all women), amenorrhoea (70%) and reversible bone loss (2-4%). Fewer patients complain of side-effects than with danazol.
Combined Oral Contraceptive Pill (COCP)
"The Pill" as it is collquially known is good for mild symptoms and simulates conditions of pregnancy.
These preparations also mimic pregnancy and can be used cyclically or continously. Fluid retention, weight gain and erratic bleeding are common side-effects. A few patients suffer symptoms which are very severe.
Danazol, gestrinone and medroxyprogesterone acetate are alternative medications but are now less frequently used because of their common adverse side-effects.
The hormonal treatment have much the same effect as each other though the first two have a longer-lasting effect on symptoms. 30% have a complete regression; 60% have a partial regression; 10% have no change; and 20-40% will have a recurrence within 5 years of ceasing hormonal treatment.
Essentially, this comes down to laparoscopic laser ablation (shooting it), diathermy (burning it) or laparotomical excision (cutting it out). Draining the cyst is less effecting than removing them (cystectomy).
Treatment is different from woman to woman. A bilateral oopherectomy and hysterectomy is good for woman who doesn't want anymore kids but women generally find it hard to get pregnant without ovaries or a uterus. Laser ablation is therefore a better option for women still wanting children but it has a high rate of recurrence.