Endometriosis is a common condition where endometrium (tissue that usually grows in the uterus) grows at an inappropriate place.
Endometriosis is a condition characterized by the abnormal growth of the endometrial tissue outside of the uterus. It is not a neoplastic disease, although the later malignant transformation is possible. These ectopic foci of the endometrial tissue respond to cyclic hormonal fluctuations almost the same as intrauterine endometrium, with proliferation, secretory activity, and cyclic sloughing of menstrual material. The prevalence of the condition is almost 10%. However, the examinations of the infertile women showed that in 30-40% of them have endometriosis.
Currently the scientists don’t know the exact cause of the condition, although several possible theories were proposed. The theory of retrograde menstruation (Sampson’s theory, the implantation theory or transplantation theory) is the most widespread theory. During a woman’s menstrual flow, some of the endometrial debris exits the uterus through the Fallopian tubes and then attaches to the lining on the surface of the abdominal cavity called peritoneum or other organs where it can invade the tissues causing endometriosis. Another theory suggests that the chronic irritation of the pelvic peritoneum may cause coelomic metaplasia (the replacement of one differentiated cell type with another mature differentiated cell type) that leads to endometriosis. The involvement of the lymph nodes could be explained by the metastasis of the endometrium through the uterine lymphatic vessels.
It is suggested that the genetic predisposition may play role in the development of endometriosis. Relatives of a woman who has endometriosis are more likely to get affected (the risk is around six-time bigger). Individual mutations of the genetic material have been associated with endometriosis such as changes on chromosome 1 near WNT4, chromosome 2 near GREB1, chromosome 6 near ID4, chromosome 7 in the 7p15.2 region, chromosome 9 near CDKN2BAS, chromosome 10 at region 10q26 and chromosome 12 near VEZT. Patient are at the age of 30-45 when the diagnosis is evaluated.
Risk factors for developing endometriosis also include:
- Early age of menarche
- Short menstrual cycles (< 27 d)
- Long duration of menstrual flow (>7 d)
- Heavy bleeding during menses
- Delayed childbearing
- Defects in the anatomy of the reproductive system
- Hypoxia and iron deficiency are associated with an early onset of the disease
There are several types of endometriosis depending on the site of the growth of the endometrial tissue. Abdominal endometriosis affects the abdominal cavity and its organs. Extra-abdominal endometriosis involves the reproductive organs. The common sites of endometriosis are the ovaries, Fallopian tubes, appendix, sigmoid colon and pelvic lymph nodes.
The type of endometriosis where the endometrium growth into the myometrium (muscular layer of the uterus) is called adenomyosis (or endometriosis interna). The symptoms of the disease vary from person to person. Usually the extent of the lesion is not related to the severity of the symptoms. Common symptoms of the disease are pelvic pain and infertility, although 25% of women with endometriosis present no symptoms at all.
Symptoms of the disease include:
– Secondary dysmenorrhea – a woman experience intense pain that occurs a few days before the menstruation and is even greater during menstruation;
– Abnormal menstruation – the menstrual flow can be extremely intense, sometimes premenstrual spotting is observed;
– Dyspareunia – pain following sexual intercourse;
– Chronic pelvic and abdominal pain – the pain is caused by the penetration of the tissues by the endometrium, inflammation and nerves’ invasion.
Sometimes the pain may appear as the result of the rupture of the cysts that occur due to endometriosis.
Other symptoms of the disease are related to the other affected organs: painful defecation, diarrhea or constipation, dysuria, back pain and even pneumothorax if the diaphragm is involved.
To evaluate the diagnosis doctor will suggest further testing. The most common pain scale for quantification of endometriosis-related pain is the visual analogue scale (VAS) and numerical rating scale (NRS). Serum marker CA 125 is often detected in case of the severe endometriosis, although it is not specific. Transvaginal ultrasound examination helps to detect ovarian and rectosigmoid endometriosis. CT and MRI are much more helpful.
Laparoscopy or laparotomy is used to confirm the diagnosis. Biopsy may be needed as well.
Several ways of treatment are possible:
1) Expectant management includes observation with administration of non-steroidal anti-inflammatory drugs – ibuprofen 800-1200 mg pro day or mefenamic acid 150-600 mg pro day. Pregnancy may cure the condition, so married women are encouraged to have conception.
2) Hormonal treatment induces atrophy of the implants of the endometrium. Combined estrogen and progestogen (oral pill), progestogens (norethisterone, dydrogesterone), danazol and GnRH (Gonadotropin-releasing hormone) analogues (leuprolide, goserelin) are administrated. Oral pills in dose of 1-2 pills pro day during 6-9 months. Danazol is recommended in dose 400-800 mg orally pro day during 6-9 months.
3) Surgical management is used to treat severe cases of endometriosis unresponsive to hormonal therapy or endometriomas are bigger than 1 cm. Conservative surgery is performed to destroy the lesions and consists of the excision of the endometrium, adhesions, resection of endometriomas, and restoration of normal pelvic anatomy of the woman’s body. Laparoscopic uterosacral nerve ablation (LUNA) is done when pain is severe. Ovarial endometrioma of the significant size is an indication to the surgical removal of the ovary. Radical surgery – hysterectomy (removal of the uterus) along with bilateral salpingo-oophorectomy (the removal of the both Fallopian tubes and ovaries) is performed when no other treatment is possible and a woman does not want to have children anymore. Laparoscopic uterosacral nerve ablation (LUNA) is done when pain is severe.