Adenomyosis
A 42-year-old woman, para 4, reports 2 years of progressively severe cramping pain starting before and lasting through her periods, with heavy bleeding. The uterus is globally enlarged to 12 weeks size, soft, and tender on bimanual examination. Endometrial biopsy shows normal secretory endometrium and ultrasound shows no discrete mass. Which of the following is the most likely diagnosis?
- A.Chronic endometritis
- B.Pelvic endometriosis
- C.Uterine adenomyosisCorrect
- D.Uterine leiomyosarcoma
Explanation
Adenomyosis is the presence of endometrial glands and stroma within the myometrium, surrounded by reactive smooth muscle hyperplasia. The classic triad in a multiparous woman aged 35 to 50 is progressive secondary dysmenorrhea, menorrhagia, and a symmetrically enlarged, soft, tender uterus, which is exactly this presentation. The heavy bleeding is explained by the increased endometrial surface area and impaired myometrial contractility, while the pain arises from cyclical bleeding and inflammation within the myometrial wall. The diffuse and symmetrical enlargement is the key discriminator from fibroids, which produce an irregular, firm, non-tender uterus with discrete masses on ultrasound. A normal endometrial biopsy is expected because the pathology lies in the myometrium, not the cavity, and the biopsy is done chiefly to exclude hyperplasia or carcinoma in a woman with abnormal bleeding. Diagnosis is usually clinical, supported by transvaginal ultrasound showing a heterogeneous myometrium with an asymmetrically thickened wall and myometrial cysts, or by MRI showing a junctional zone thicker than 12 mm; histology after hysterectomy remains definitive. Medical treatment options include the levonorgestrel intrauterine system, combined hormonal contraception, and tranexamic acid, with hysterectomy as the definitive cure for women who have completed childbearing.
Why each option
- A.
- Endometritis usually follows delivery or an intrauterine procedure and causes fever and foul discharge, and the biopsy would show plasma cell infiltration.
- B.
- Endometriosis causes dysmenorrhea, deep dyspareunia, and infertility, but the uterus is typically normal in size and the tenderness is adnexal or in the pouch of Douglas.
- C.
- Correct. Progressive secondary dysmenorrhea with menorrhagia and a diffusely enlarged, soft, tender uterus and a normal endometrial biopsy is the classic picture.
- D.
- Leiomyosarcoma causes rapid uterine enlargement, often with postmenopausal bleeding and constitutional symptoms, and the uterus is irregular rather than diffusely enlarged.
Reference: Berek & Novak's Gynecology, 16th ed., 2020, Adenomyosis; UpToDate 2025, Uterine adenomyosis
This is one of 3,306 questions in the MedBoardSA SMLE bank, with timed test mode, tutor mode, and progress tracking by topic.
Practise the full bank