Adenomyosis

Aka: Adenomyosis, Endometriosis of Uterus

1. See Also
   1. Abnormal Uterine Bleeding
   2. Endometriosis
   3. Pelvic Pain
   4. Uterine Fibroids
   5. Dysmenorrhea
2. Definitions
   1. Adenomyosis
      1. Endometrial glands embedded within the uterine myometrium
      2. Contrast with Endometriosis, in which endometrial glands are embedded in tissue outside the Uterus
3. Risk Factors
   1. Multiparous women
   2. Age over 40 years old
   3. Prior cesarean delivery
   4. Prior uterine surgery
4. Epidemiology
   1. Incidence: 1% (29 per 10,000 person years over 10 years)
      1. Symptomatic in >90% of cases in this series
      2. Yu (2020) Am J Obstet Gynecol 223(1): 94 [PubMed]
   2. Prevalence data is highly variable
      1. Original Prevalence of 10 to 35% was obtained from Hysterectomy tissue samples
         1. However, there are no standardized histologic criteria for the Adenomyosis diagnosis
      2. One Ultrasound-based study in symptomatic women identified Adenomyosis in 20%
         1. Naftalin (2012) Human Reprod 27(12):3432-9 [PubMed]
      3. Prevalence varies by age
         1. Overall Prevalence (female patients of all ages): 0.8%
         2. Age 41 to 45 years old (peak age): 1.5%
5. Pathophysiology
   1. Endometrial glands and stroma embed within the myometrium of the Uterus
      1. Colloquially known as Endometriosis of the Uterus (or internal Endometriosis)
   2. Pathogenesis theories
      1. Basalis endometrium, on injury, invaginates into the myometrium via an interrupted junctional zone OR
      2. Metaplasia of pluripotent Mullerian duct remnants
   3. Types
      1. Diffuse involvement of myometrium
      2. Focal
6. Symptoms
   1. Asymptomatic in one third of patients
   2. Symptom onset typically at age 40 to 50 years old
   3. Dysmenorrhea (Painful Menstrual Periods, occurring in 15 to 30% of patients)
      1. May be worse in comorbid Uterine Fibroids
   4. Menorrhagia (heavy menstrual periods, occurring in 40-60% of patients)
   5. Metrorrhagia (prolonged menstrual periods)
   6. Other more variable symptoms
      1. Dyspareunia
      2. Chronic Pelvic Pain
      3. Infertility
7. Signs
   1. Enlarged Uterus that is tender and boggy
8. Associated Conditions
   1. Uterine Fibroids (50%)
   2. Endometriosis (11%)
9. Differential Diagnosis
   1. See Abnormal Uterine Bleeding Causes
   2. See Dysmenorrhea
   3. See Chronic Pelvic Pain Causes
   4. See Dyspareunia
10. Imaging
    1. Transvaginal Ultrasound
       1. Efficacy
          1. Test Sensitivity: 83.8%
          2. Test Specificity: 63.9%
       2. Findings
          1. Globular Uterus
          2. Fan-shaped shadowing
          3. Indistinct margin between outer myometrium and junctional zone
          4. Cystic changes involve the junctional zone and myometrium
          5. Hyperechoic islands within the junctional zone
       3. References
          1. Andes (2018) J Minim Invasive Gynecol 25(2): 257-64 [PubMed]
    2. MRI Pelvis
       1. Indicated in non-diagnostic Ultrasound
       2. Test Sensitivity: 77%
       3. Test Specificity: 89%
       4. Bazot (2018) Fertil Steril 109(3): 389-97 [PubMed]
       5. Liu (2021) J Ultrasound Med 40(11): 2289-306 [PubMed]
    3. Hysteroscopy
       1. Hypervascularization
       2. Endometrial defects
       3. Submucosal hemorrhagic cysts
11. Management
    1. Non-surgical symptomatic management
       1. See Dysmenorrhea
       2. NSAIDs
       3. Hormonal management
          1. Oral Contraceptives
          2. Progestin-Releasing IUD (e.g. Mirena)
          3. Gonadotropin-Releasing Hormone analogues and antagonists
    2. Surgical Management
       1. Hysterectomy (80% of women with Adenomyosis)
       2. Uterine artery embolization
12. References
    1. Osayande (2014) Am Fam Physician 89(5): 341-6 [PubMed]
    2. Schrager (2022) Am Fam Physician 105(1): 33-8 [PubMed]
    3. Taran (2013) Geburtshilfe Frauenheilkd 73(9):924-31 +PMID: 24771944 [PubMed]