Endometriosis: Definition, Diagnosis, and Management
Endometriosis is an inflammatory disease characterized by endometrial-like tissue growing outside the uterus, affecting approximately 10% of individuals assigned female at birth during their reproductive years (approximately 176 million women worldwide), causing pelvic pain, infertility, and systemic effects that significantly impact quality of life. 1
Definition and Pathophysiology
Endometriosis is defined by the presence of endometrial-like tissue (lesions) outside the uterine cavity, typically in the pelvis, causing chronic inflammation and fibrosis 1. While traditionally viewed as a gynecological condition, recent evidence indicates endometriosis is a systemic disease with effects beyond the pelvis, including:
- Metabolic alterations in liver and adipose tissue
- Systemic inflammation
- Gene expression changes in the brain leading to pain sensitization and mood disorders 2
Classification
Endometriosis is classified based on location and depth 1:
- Peritoneal (superficial): Lesions on the peritoneal surface
- Ovarian endometriomas: Cystic lesions within the ovaries
- Deep endometriosis (DE): Extends deeper than 5mm under the peritoneal surface or involves/distorts bowel, bladder, ureter, or vagina
Clinical Presentation
The disease presents with varying symptoms 1, 3:
- Pain manifestations (90% of patients):
- Dysmenorrhea (painful periods)
- Nonmenstrual pelvic pain
- Dyspareunia (painful intercourse)
- Fertility issues (26-50% report infertility)
- Other symptoms:
- Fatigue
- Gastrointestinal symptoms
- Urinary symptoms
- Mood disorders
Risk Factors
Several risk factors have been identified 3:
- Younger age at menarche
- Shorter menstrual cycle length
- Lower body mass index
- Nulliparity
- Congenital obstructive müllerian anomalies
Diagnosis
Diagnosis of endometriosis is often significantly delayed, with an average delay of 5-12 years after symptom onset 1, 3. Most women consult 3 or more clinicians prior to diagnosis.
The modern diagnostic approach includes:
- Clinical diagnosis based on symptoms and physical examination
- Imaging support:
- Transvaginal ultrasound (TVUS) - particularly effective for ovarian endometriomas and deep endometriosis
- Pelvic MRI - helpful for complex or deep lesions
It's important to note that normal physical examination and imaging do not exclude the diagnosis 3. Definitive diagnosis traditionally requires surgical visualization of lesions, typically via laparoscopy, with histological verification 4.
Treatment
Treatment depends on the patient's goals and symptom severity 1:
First-line treatments:
- Hormonal medications for symptomatic premenopausal women not currently seeking pregnancy:
- Combined oral contraceptives
- Progestin-only options
- These lead to clinically significant pain reduction compared to placebo 3
Second-line treatments:
- GnRH agonists and antagonists
Third-line treatments:
- Aromatase inhibitors
Surgical options:
- Laparoscopic removal of lesions when hormonal therapies are ineffective or contraindicated
- Hysterectomy with surgical removal of lesions for refractory cases
Treatment Limitations
Important treatment limitations to consider:
- 11-19% of individuals have no pain reduction with hormonal medications
- 25-34% experience recurrent pelvic pain within 12 months of discontinuing hormonal treatment
- Approximately 25% of patients who undergo hysterectomy experience recurrent pelvic pain
- 10% require additional surgery after hysterectomy 3
Impact on Quality of Life
Endometriosis substantially affects quality of life, interfering with daily activities, work, and relationships, with an economic burden estimated at $69.4 billion annually 1. The impact is comparable to other chronic conditions such as type 2 diabetes mellitus, Crohn's disease, and rheumatoid arthritis 4.