A 32-year-old Indian woman presents with severe dysmenorrhea and chronic pelvic pain for the past 3 years. She reports that pain worsens progressively during menstruation and persists throughout her cycle. On examination, the uterus is tender, boggy, and slightly enlarged (approximately 12 weeks size). Transvaginal ultrasound shows heterogeneous myometrial echotexture with ill-defined junctional zone and multiple small cystic spaces within the myometrium. Serum CA-125 is mildly elevated at 48 U/mL. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Adenomyosis **Key Point:** Adenomyosis is characterized by ectopic endometrial glands and stroma within the myometrium (invagination into muscle layer), distinct from endometriosis which involves peritoneal implants outside the uterus. ### Diagnostic Features Present in This Case | Feature | Finding in Case | Significance | |---------|-----------------|---------------| | **Age** | 32 years (reproductive age) | Peak incidence 40–50 years, but common in 30s | | **Dysmenorrhea** | Severe, progressive | Hallmark symptom; pain worsens with menses | | **Pelvic pain** | Chronic, throughout cycle | Reflects deep myometrial involvement | | **Uterine findings** | Tender, boggy, enlarged | Diffuse myometrial disease, not focal | | **Ultrasound** | Heterogeneous myometrium, ill-defined junctional zone, cystic spaces | Pathognomonic for adenomyosis | | **CA-125** | Mildly elevated | Non-specific but supports adenomyosis | **High-Yield:** The **junctional zone abnormality** on transvaginal ultrasound (>12 mm thickness, irregular borders, heterogeneity) is the most specific imaging criterion for adenomyosis. The presence of **myometrial cysts** (adenomyotic cysts) further supports the diagnosis. **Clinical Pearl:** Adenomyosis classically presents as a **diffusely enlarged, tender, boggy uterus** on bimanual examination—the "bulky uterus" sign. This contrasts with the focal masses of fibroids. ### Pathophysiology 1. Invagination of basalis layer endometrium into myometrium 2. Disruption of junctional zone architecture 3. Increased myometrial contractility and inflammation 4. Elevated prostaglandins → dysmenorrhea and chronic pain **Mnemonic:** **ADENOMYOSIS = Adenoma-like + Myometrial + Invasion + Osis** (benign infiltration of endometrium into muscle) ### Why Transvaginal Ultrasound is Superior - Sensitivity 60–90% for adenomyosis (MRI also excellent but less available in India) - Junctional zone irregularity is the most specific finding - Can assess myometrial thickness and cystic changes - Non-invasive and reproducible **Warning:** Adenomyosis cannot be definitively diagnosed without histology (endometrial invasion >2.5 mm into myometrium), but imaging + clinical features are sufficient for clinical diagnosis and management. [cite:Jeffcoate's Principles of Gynaecology Ch 19]