Adenomyosis

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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. Adenomyosis: Gross and microscopic views

⭐ 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.

Transvaginal ultrasound of adenomyosis

⭐ 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.

Practice Questions: Adenomyosis

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Which of the following statements accurately describes adenomyosis?

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Flashcards: Adenomyosis

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_____ theory of celomic metaplasia states that metaplastic changes in embryonic mesothelium which responds to hormone stimulation is the etiology of endometriosis

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_____ theory of celomic metaplasia states that metaplastic changes in embryonic mesothelium which responds to hormone stimulation is the etiology of endometriosis

Meyer and Ivanoff's

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