Endometriosis

Detailed Overview

The exact cause is unknown, but Sampson theory of retrograde menstruation is the most widely accepted. The ectopic endometrial tissue responds to cyclic ovarian hormones, causing localized bleeding, inflammation, and fibrosis/adhesions. Endometriosis significantly impacts quality of life through severe dysmenorrhea, deep dyspareunia, and chronic pelvic pain. Diagnosis is often delayed by 7-10 years from symptom onset.

Epidemiology & Demographics

Affects 10% of reproductive-aged women. Prevalence is 30-50% in women with chronic pelvic pain or infertility. Peak incidence is between ages 25-35.

Etiological Mechanism

Multifactorial. Retrograde menstruation (Sampson theory) combined with altered immune clearance allows viable endometrial cells to implant on the peritoneum. Coelomic metaplasia and lymphatic spread are alternative theories for extra-pelvic disease.

Primary Causes

Idiopathic, though heavily influenced by genetic predisposition, immune dysfunction, and estrogen exposure.

• Nulliparity: Never having given birth increases uninterrupted menstrual cycles.
• Early menarche / Late menopause: Prolonged lifetime exposure to endogenous estrogen.
• First-degree relative with endometriosis: 7 to 10-fold increased risk.

Ectopic endometrial tissue contains estrogen receptors and aromatase, allowing local estrogen production that drives tissue proliferation. Unlike normal endometrium, ectopic tissue is resistant to progesterone-induced apoptosis. During menstruation, these lesions bleed locally. Because the blood cannot be expelled from the body, it triggers a robust macrophage-driven inflammatory cascade. This chronic inflammation produces cytokines and prostaglandins, stimulating sensory nerve fibers (causing severe pain). Over time, organized inflammatory exudates lead to dense fibrous adhesions that distort pelvic anatomy (e.g., tethering the ovaries to the bowel), obstructing fallopian tubes and impairing oocyte release, causing infertility. Ovarian implants form cystic collections of old, dark blood known as endometriomas (chocolate cysts).

Characteristic Clinical Presentation

• Severe Dysmenorrhea: Painful periods that do not respond well to NSAIDs, often starting days before bleeding.
• Chronic Pelvic Pain: Non-cyclic aching pain in the lower abdomen or back.
• Deep Dyspareunia: Pain deep in the pelvis during or after sexual intercourse.
• Dyschezia and Dysuria: Painful bowel movements or urination, typically exacerbating during menstruation.

Physical Examination Signs

• Nodularity and tenderness along the uterosacral ligaments on bimanual exam.
• A fixed, retroverted uterus due to posterior cul-de-sac adhesions.
• Palpable adnexal mass (endometrioma) on pelvic exam.

• Infertility: Occurs in 30-50% of patients due to distorted pelvic anatomy and inflammatory hostile environment for sperm/embryos.
• Ruptured Endometrioma: Spillage of irritating cystic contents into the peritoneum causing an acute surgical abdomen.
• Bowel or Ureteral Obstruction: Deep infiltrating endometriosis (DIE) invading the colon or ureters, risking renal loss.

Diagnostic Criteria & Guidelines

Definitive diagnosis requires surgical visualization (laparoscopy) and histologic confirmation of endometrial glands and stroma. However, empiric medical treatment is usually started based on clinical suspicion without prior surgery.

Differential Diagnosis

• Pelvic Inflammatory Disease (PID)
• Adenomyosis
• Ovarian cysts (hemorrhagic, dermoid)
• Irritable Bowel Syndrome (IBS)

Laboratory Tests & Biomarkers

• CA-125: May be mildly elevated (>35 U/mL) in moderate-severe endometriosis, but low specificity limits its use.

Imaging Modalities & Findings

• Transvaginal Ultrasound (TVUS): Ovarian endometriomas appear as cysts with homogeneous, low-level echoes ("ground glass" appearance). Used to map deep infiltrating nodules.
• Pelvic MRI: T1 hyperintense and T2 hypointense (shading sign) cysts. Best for mapping deep infiltrating disease prior to surgery.

• Stage I (Minimal)
  Few superficial implants with no adhesions.
• Stage II (Mild)
  More numerous, deeper implants, but no significant adhesions.
• Stage III (Moderate)
  Many deep implants, small endometriomas, and filmy adhesions.
• Stage IV (Severe)
  Large endometriomas, dense pelvic adhesions obliterating the cul-de-sac ("frozen pelvis").

Second-Line & Adjunctive Therapy

GnRH agonists (Leuprolide 3.75 mg IM monthly) or GnRH antagonists (Elagolix 150 mg PO daily) to induce a hypoestrogenic state. Add-back hormone therapy (low dose estrogen/progesterone) is required to prevent bone loss and severe hot flashes if used >6 months.

Surgical & Procedural Management

Laparoscopic excision or ablation of endometriotic lesions and adhesiolysis for pain refractory to medical management or for fertility enhancement. Excision of endometriomas. Definitive surgery (hysterectomy with bilateral salpingo-oophorectomy) is a last resort for severe refractory pain in patients done childbearing.

Recommended Lifestyle Changes

• Regular aerobic exercise, which may decrease estrogen levels and release endorphins.
• Anti-inflammatory diets (high omega-3s) may provide symptomatic relief.

Patient Counseling & Advice

Acknowledge that her pain is real (validation is crucial due to high rates of medical gaslighting in endometriosis). Explain that medical therapy manages pain but does not cure the disease or improve fertility.

Follow-Up & Monitoring Schedule

Monitor pain scores every 3-6 months after starting therapy. Serial ultrasounds yearly for patients with known, managed endometriomas.

Preventive Strategies

Prolonged use of combined oral contraceptives from an early reproductive age can reduce risk, but primary prevention is not fully established.

A chronic, recurring condition. Symptoms typically regress post-menopause. With appropriate surgical and medical management, 60% of infertile women can conceive.