Adenomyosis

Adenomyosis - Uterine Invader

• Definition: Benign invasion of endometrial glands & stroma into the myometrium, >2.5 mm from basalis layer, causing diffuse, globular uterine enlargement.
• Prevalence: Common, affecting up to 20-35% of women, particularly those undergoing hysterectomy for benign conditions.
• Typical Age: Multiparous women in late reproductive years (35-50 years).
• Pathogenesis: Estrogen-dependent; theories include endometrial invagination, metaplasia of Müllerian remnants, or lymphatic/vascular spread.

⭐ Classic triad: Menorrhagia (heavy menstrual bleeding), dysmenorrhea (painful periods), and a symmetrically enlarged, tender ("boggy") uterus on examination.

Adenomyosis - Inner Workings

• Pathogenesis Theories:
  • Invagination Theory: Endometrial basalis (stratum basalis) invades the myometrium, disrupting the endometrial-myometrial interface (EMI).
  • Metaplasia Theory: De novo formation from Müllerian remnants or differentiated stem cells within the myometrium.
• Hormonal Influence:
  • Estrogen & Progesterone dependent: Ectopic glands/stroma respond to cyclic hormones.
  • Local hyperestrogenism: ↑ aromatase expression in adenomyotic foci converts androgens to estrogen, promoting growth.
• Risk Factors:
  • Parity (multiparous > nulliparous).
  • Prior uterine surgery (e.g., C-section, D&C, myomectomy).
  • Early menarche (< 10 years).
  • Short menstrual cycles (< 25 days).

⭐ Junctional zone (JZ) thickening > 12 mm on MRI is a key diagnostic criterion.

Adenomyosis - Inner Workings

• Pathogenesis Theories:
  • Invagination Theory: Endometrial basalis (stratum basalis) invades the myometrium, disrupting the endometrial-myometrial interface (EMI).
  • Metaplasia Theory: De novo formation from Müllerian remnants or differentiated stem cells within the myometrium.
• Hormonal Influence:
  • Estrogen & Progesterone dependent: Ectopic glands/stroma respond to cyclic hormones.
  • Local hyperestrogenism: ↑ aromatase expression in adenomyotic foci converts androgens to estrogen, promoting growth.
• Risk Factors:
  • Parity (multiparous > nulliparous).
  • Prior uterine surgery (e.g., C-section, D&C, myomectomy).
  • Early menarche (< 10 years).
  • Short menstrual cycles (< 25 days).

⭐ Junctional zone (JZ) thickening > 12 mm on MRI is a key diagnostic criterion.

Adenomyosis - Telling Signs

• Symptoms:
  • Heavy Menstrual Bleeding (HMB) / Menorrhagia: Most common.
  • Dysmenorrhea: Severe, often worsening with age.
  • Chronic Pelvic Pain (CPP).
  • Dyspareunia (deep).
  • Subfertility or infertility.
• Signs (Pelvic Examination):
  • Uterus: Symmetrically enlarged (globular), often < 12 weeks gestational size.
  • Consistency: Boggy, "woody" feel.
  • Tenderness: Especially premenstrually.
• Asymptomatic: Up to 1/3rd of women may have no symptoms.

⭐ Exam Favourite: Adenomyosis is often described as "endometriosis interna" due to ectopic endometrial tissue within the myometrium.

Adenomyosis - Diagnostic Clues

• Transvaginal Ultrasound (TVUS): Preferred initial modality.
  • Uterine features: Globular, enlarged uterus; asymmetric thickening.
  • Myometrial texture: Heterogeneous, ill-defined areas.
  • Myometrial cysts: Anechoic spaces within myometrium.
  • Endometrial-Myometrial Junction (EMJ): Indistinct, blurred, or irregular.
  • Specific signs: 'Question mark' sign, subendometrial lines/striations.
• Magnetic Resonance Imaging (MRI): Higher specificity; used if TVUS is equivocal or for surgical planning.
  • Primary finding: Diffuse or focal thickening of the junctional zone (JZ) > 12mm on T2-weighted images.
  • Other: High-signal intensity foci (ectopic endometrial tissue, hemorrhage) within myometrium on T1WI.
• Histopathology: Gold standard for definitive diagnosis.
  • Requires uterine specimen (post-hysterectomy).
  • Demonstrates endometrial glands and stroma located > 2.5mm deep within the myometrium.

⭐ Histopathology, confirming endometrial glands and stroma >2.5mm deep in myometrium, is the gold standard for adenomyosis diagnosis, typically post-hysterectomy.

Adenomyosis - Treatment Tactics

• Medical: NSAIDs for analgesia. Hormonal options include COCPs, progestins (oral, injectable, LNG-IUS), and GnRH analogs (e.g., Leuprolide) for temporary amenorrhea & uterine shrinkage.
• Surgical: Hysterectomy is definitive. Uterine-sparing options: uterine artery embolization (UAE), MRI-guided focused ultrasound (MRgFUS).

⭐ Levonorgestrel-releasing intrauterine system (LNG-IUS) is highly effective for adenomyosis-associated heavy menstrual bleeding and dysmenorrhea, often considered first-line hormonal therapy when fertility is not desired immediately.

High‑Yield Points - ⚡ Biggest Takeaways

• Ectopic endometrial glands and stroma located deep within the myometrium.
• Classic triad: severe dysmenorrhea, heavy menstrual bleeding (HMB), and chronic pelvic pain.
• Uterus is often globular, symmetrically enlarged, boggy, and tender.
• Transvaginal ultrasound (TVS) is the primary imaging; MRI is more specific for diagnosis.
• Definitive diagnosis is confirmed by histopathology post-hysterectomy.
• Management includes hormonal therapies (e.g., LNG-IUS, GnRH agonists) or hysterectomy.
• Associated with infertility and adverse pregnancy outcomes.