Mastering Medical
USMLE Step 2 CK · Obstetrics & Gynecology

Endometriosis vs Adenomyosis

How to tell Endometriosis and Adenomyosis apart when a board question makes them look alike.

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A diffusely enlarged boggy uterus on bimanual exam points to adenomyosis.

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EndometriosisAdenomyosis
Key clue

Cyclic pelvic pain with dysmenorrhea, deep dyspareunia, and infertility with a normal-sized or fixed retroverted uterus suggests endometriosis.

Heavy painful menses with a diffusely enlarged boggy tender uterus suggests adenomyosis.

Mechanism

Ectopic endometrial implants bleed cyclically, driving inflammation, fibrosis, and adhesion-related pain.

Endometrial glands invading the myometrium cause uterine hypertrophy and diffuse menstrual pain and bleeding.

Labs and tests

Pelvic ultrasound can be normal or show endometrioma, while definitive diagnosis is laparoscopic visualization with biopsy when diagnosis is uncertain or infertility workup requires confirmation.

Transvaginal ultrasound or MRI may show asymmetric myometrial thickening and myometrial cysts, with enlarged globular uterus on exam as key clinical clue.

The trap

Severe dysmenorrhea is attributed to endometriosis in every case, but uterine enlargement and heavy bleeding favor adenomyosis and shift management toward hormonal bleeding control or hysterectomy when refractory.

The repair move

Next best step: exclude pregnancy and structural emergencies, then use pelvic exam to branch diagnosis. For adenomyosis symptoms in stable patients, start NSAIDs plus levonorgestrel intrauterine system or combined hormonal therapy for bleeding and pain control. For endometriosis pattern with infertility or refractory pain, begin empiric hormonal suppression such as combined oral contraceptives or progestin, and proceed to diagnostic or therapeutic laparoscopy when symptoms persist or fertility planning requires.

Try a free question

Core

A 42-year-old woman has heavy menstrual bleeding and progressive dysmenorrhea for 1 year. BP 130/82 mm Hg, HR 80/min, temp 36.7 C. Bimanual exam reveals a uniformly enlarged tender uterus. What is the most likely diagnosis?

Show answer and explanation

Answer: A. Adenomyosis. A uniformly enlarged boggy tender uterus with heavy painful menses is most consistent with adenomyosis.

Why the other choices are tempting

  • B. Wrong because endometriosis usually does not produce a diffusely enlarged boggy uterus.
  • C. Wrong because polycystic ovary syndrome is an ovulatory and androgen disorder, not this uterine exam pattern.
  • D. Wrong because cervicitis does not explain diffuse uterine enlargement and menorrhagia.
  • E. Wrong because chronic cyclic symptoms and exam findings are not typical for ectopic pregnancy.

Flashcards

Tap a card to flip it.

What bimanual exam finding most strongly supports adenomyosis over endometriosis?

A diffusely enlarged boggy tender uterus strongly favors adenomyosis.

Which symptom cluster is most suggestive of endometriosis?

Cyclic pelvic pain with deep dyspareunia and infertility in a patient with otherwise normal uterine size suggests endometriosis.

Quick answers

What is the fastest way to tell Endometriosis from Adenomyosis?

A diffusely enlarged boggy uterus on bimanual exam points to adenomyosis.

What is the key clue for Endometriosis?

Cyclic pelvic pain with dysmenorrhea, deep dyspareunia, and infertility with a normal-sized or fixed retroverted uterus suggests endometriosis.

What is the key clue for Adenomyosis?

Heavy painful menses with a diffusely enlarged boggy tender uterus suggests adenomyosis.

What is the common trap with Endometriosis vs Adenomyosis?

Severe dysmenorrhea is attributed to endometriosis in every case, but uterine enlargement and heavy bleeding favor adenomyosis and shift management toward hormonal bleeding control or hysterectomy when refractory.