Endometriosis (Gynecologists' Lecture)

Endo- means internal and -metrium means womb, so endometrium is the innermost layer of the womb, and endometriosis is where these endometrial cells grow outside of the womb.
The female internal sex organs are the ovaries, which are the female gonads; the fallopian tubes, two muscular tubes that connect the ovaries to the uterus; and the uterus, which is the strong muscular sack that a fetus can develop in.
It’s a hollow organ that sits behind the urinary bladder and in front of the rectum.
The top of the uterus above the openings of the fallopian tubes is called the fundus, and the region below the openings is called the uterine body.
The uterus tapers down into the uterine isthmus and finally the cervix, which protrudes into the vagina.
Now, whatever the cause, endometriosis implants are benign so they don’t grow out of control like cancerous cells.
However, because they’re functionally the same as the epithelial cells found within the uterus, they have the same estrogen receptor.
So they go through the same proliferation, secretion, and menstruation cycle just like the normal endometrial cells.
But, there are two key differences between normal endometrial cells and endometriosis implants.
First, the implanted cells contain high levels of the enzyme aromatase, which allows them to produce their own estrogen.
Second the implanted cells release pro-inflammatory factors which causes inflammation and scarring.
These scars could cause adhesion which is the binding of different organs or structures to each other, affecting their normal anatomical placement.
Both the pro-inflammatory factors and estrogen also promotes the growth of new blood vessels which nourish the implant.
Now, changes in hormone levels and the chronic inflammation will cause the implant to bleed, especially during menstruation.
If the implant is on an ovary, it could form an endometriomas, or chocolate cysts, which contains the old, dark blood and shed tissue.
When these get too large, they will rupture and spill their contents, resulting in a lot of pain and even more inflammation.
Endometrioma cells also tend to develop mutations in certain genes, including PTEN and ARID1A, which increase the risk of developing ovarian carcinoma.
The symptoms of endometriosis can be quite debilitating and are related to the location of the endometrial cells.
Most commonly, endometriosis on the reproductive organs will causes pelvic pain, bleeding, dysmenorrhea, or painful menstruation, and dyspareunia, or painful sexual intercourse.
If it involves the pouch of Douglas, a section of the peritoneum located between the rear wall of the uterus and the rectum, it can cause dyschezia, or pain with defecation.
It can also cause urgent, frequent and sometimes painful urination if it involves the bladder, and abdominal pain if involves the intestines.
All of these symptoms will often vary with the hormone changes throughout the menstrual cycle, and often gets worse during menstrual periods.
About 30-40% of women with endometriosis are subfertile.
The exact link between infertility and endometriosis isn’t totally clear.
It’s believed that the inflammation that comes with endometriosis can damage or scar the reproductive structures, thus inhibiting the release of the egg or its movement through the fallopian tube.
Damage to the uterus can also make the implantation of the gamete more difficult.
The good news is that pregnancy is often still possible, depending on the severity of the endometriosis and the effectiveness of the treatment.
The best way to diagnose endometriosis is through laparoscopy, and the diagnosis can be confirmed with a biopsy.
Treatment is focused on managing pain, trying to limit the progression of the implants, and addressing the associated subfertility.
Common hormonal medications that are used to treat pain include: combined estrogen-progesterone oral contraceptive pills, which relieve pain through ovarian suppression; progesterone analogs like medroxyprogesterone and levonorgesterol, which inhibit growth of the endometrium; danazol, which is a steroid that inhibits mid-cycle surges of follicular stimulating hormone and luteinizing hormone and prevents steroidogenesis in the corpus luteum; and gonadotropin-releasing hormone modulators, which cause a decrease in estrogen levels.
Surgical options are available for severe cases.
If the woman still wants to have children, the surgery involves only excision of endometrial implants, endometriomas, and adhesions.
If she has completed her childbearing or if the pain is too debilitating, a hysterectomy and oophorectomy with excision of any other endometrial implants is done.
Whatever the treatment, once menopause hits and hormone levels fall, the symptoms generally goes away.