An estrogen-dependent growth of endometrial-like tissue outside the uterus inducing a chronic inflammatory response
Extent of disease varies but pelvic organs (especially ovaries) and peritoneum are frequently affected
Complications include pain, fertility problems and risk of developing ovarian cancer
Epidemiology
Affects 5-10% of reproductive-aged women (most common between 22-29 years of age) and has considerable impact on quality of life
Prevalence is higher in Asian women while a lower incidence is found among African women as compared to Caucasians
Etiology
Remains unclear but theories include:
Retrograde menstruation (Sampson’s theory)
Immune system problems
Metaplastic changes of the peritoneal coelomic mesothelial cells
Spread of ectopic menstrual tissue via the bloodstream or lymphatic system
Differentiation of cells from bone marrow into ectopic endometrial tissue
Increase in estrogen sensitivity with increase in progesterone resistance
Risk Factors
Genetics, particularly among the patient’s first-degree relatives
Prolonged exposure to endogenous estrogen (early menarche or late menopause)
Short menstrual cycle
Low birth weight
Low body mass index (BMI)
Obstruction of menstrual flow (eg Müllerian anomalies)
High consumption of red meat and trans fat
Types of Endometriosis
Ovarian endometriomas or chocolate cysts
Superficial peritoneal endometriosis
Deep infiltrating endometriosis (lesions that penetrate >5 mm to the peritoneum)
Disseminated endometriosis
Signs and Symptoms
Severe dysmenorrhea
Chronic pelvic pain (found in 70-82% of patients)
Dyspareunia (suggests deep posterior infiltration)
Infertility (21% prevalence rate)
Other symptoms may include pain on ovulation, non-cyclical pelvic pain, cyclical bowel or bladder symptoms with or without abnormal bleeding or pain, dyschezia, dysuria, chronic fatigue, abdominal or lower back discomfort
In adolescents, endometriosis is the most common cause of secondary dysmenorrhea
Although it is vital to consider the patient’s complaints affecting physical, mental and social well-being, it shouldbe noted that patients with endometriosis may be completely asymptomatic (with 2-22% prevalence rate)
