Epidemiology

Etiology

In endometriosis, endometrial tissue occurs outside of the uterus.
- It’s adenomyosis if in uterus.
Common locations of endometriotic implants include:
- Pelvic organs
  - Ovaries: most common site; often affected bilaterally
  - Rectouterine pouch
  - Fallopian tubes
  - Bladder
  - Cervix
- Peritoneum
- Extrapelvic organs (e.g., lung or diaphragm): less commonly affected
Regardless of where the endometrial tissue is located, it reacts to the hormone cycle in much the same way as the endometrium and proliferates under the influence of estrogen.
Endometriotic implants result in:
- ↑ Production of inflammatory and pain mediators
- Anatomical changes (e.g., pelvic adhesions) → infertility

Chronic pelvic pain that worsens before the onset of menses
Infertility
- Endometriosis causes inflammation and adhesions that can change pelvic anatomy, altering egg quality and impairing implantation. 25–50% of infertile women have endometriosis.
Dysmenorrhea
Pre- or postmenstrual bleeding
Dyspareunia

Normal endometrial glands
Normal endometrial stroma
Preponderance of hemosiderin laden macrophages due to cyclic hemorrhages into endometriomas

Tip

Endometriosis: fixed, immobile uterus (due to pelvic adhesion)

Adenomyosis: enlarged, boggy, tender uterus

Definition: benign disease characterized by the occurrence of endometrial tissue within the myometrium due to hyperplasia of the endometrial basal layer
Epidemiology: peak incidence at 35–50 years
Clinical features
- May be asymptomatic
- Dysmenorrhea
- Abnormal uterine bleeding
- Chronic pelvic pain, aggravated during menses
- Globular, uniformly enlarged uterus that is soft but tender on palpation
  - Differ from Uterine leiomyoma, which shows irregularly enlarged, firm uterine
Diagnostics
- Diagnosis is clinical and may be supported by transvaginal ultrasound and MRI findings
  - Asymmetric myometrial wall thickening
  - Myometrial cysts

Ovaries
- Gunshot lesions or powder-burn lesions
  - Black, yellow-brown, or bluish nodules or cystic structures
  - Seen on the serosal surfaces of the ovaries and peritoneum
- Ovarian endometriomas or chocolate cysts: cyst-like structures that contain blood, fluid, and menstrual debris

Mild to moderate pelvic pain without complications
- Empiric treatment with NSAIDs and continuous hormonal contraceptives
- NSAIDs alone if pregnancy is desired
- Synthetic androgens (e.g., danazol)
Severe symptoms: GnRH agonists (e.g., buserelin, goserelin) and estrogen-progestin OCPs
- OCPs are to avoid hypoestrogenic side effects