Endometriosis and Adenomyosis: Decoding Their Contribution To Pelvic Pain

Endometriosis and adenomyosis affect millions of women worldwide. While they share certain similarities, they also exhibit differences in their pathophysiology, clinical presentation, and management. Let’s compare and contrast endometriosis and adenomyosis, shedding light on their associations and highlighting relevant references.

Similarities

Both endometriosis and adenomyosis involve the growth of endometrial-like tissue outside the uterine cavity. This ectopic tissue remains responsive to hormonal changes, leading to inflammation, pain, and other similar symptoms that can significantly interfere with the quality of life (1).

Both conditions predominantly affect women of reproductive age and are associated with dysmenorrhea (painful periods), dyspareunia (painful intercourse), and infertility (2). The exact cause of these conditions remains unclear, but a combination of genetic, hormonal, and immune factors is thought to be involved in both (3). Both can also continue beyond or even be present initially after menopause.

Differences

1. Anatomical location 

While both endometriosis and adenomyosis involve the growth of ectopic endometrial-like tissue, they differ in anatomical location. Endometriosis is characterized by the presence of endometrial-like tissue outside the uterus, commonly on the ovaries, fallopian tubes, the peritoneum (pelvic and abdominal skin-like lining), and other organs (4). In contrast, adenomyosis is defined by the invasion of endometrial-like tissue into the myometrium (muscular wall) of the uterus (5).

2. Prevalence

Endometriosis affects approximately 10% of women of reproductive age, while adenomyosis is thought to impact between 20% and 35% of women in this age group (6). But the true prevalence of both conditions may be underestimated due to the invasive nature of diagnostic procedures and non-specific symptoms (7).

3. Diagnosis

The gold standard for diagnosing endometriosis is surgery using laparoscopy or robotics, both minimally invasive surgical procedures that allow for direct visualization and, if necessary, excision of endometrial-like tissue lesions (8). In contrast, adenomyosis is typically suspected using imaging techniques such as transvaginal ultrasound or magnetic resonance imaging (MRI). It can usually only be confirmed by the pathologist when the uterus is removed (9). An accurate preoperative biopsy is very difficult, although removal of discrete adenomyomas, leaving the uterus behind, is sometimes possible when the adenomyosis is not diffuse throughout the myometrium of the uterus.

4. Treatment

Both conditions are managed with a combination of medical and surgical therapies, depending on the severity of symptoms and reproductive goals. Hormonal therapies, including oral contraceptives, progestins, and gonadotropin-releasing hormone (GnRH) agonists and antagonists, are commonly used to manage symptoms in both endometriosis and adenomyosis (10). Integrative measures, including anti-inflammatory and anti-oxidant hormone-modulating nutrition and lifestyle modification, can also help not just control symptoms but also contribute to treating the root causes. 

However, surgical approaches differ between the two conditions. In endometriosis, the preferred surgical intervention is laparoscopic and robotic excision of the ectopic tissue (11). For adenomyosis, hysterectomy (removal of the uterus) may be considered in severe cases where fertility preservation is not a concern (12). Again, in some cases, when discrete adenomyomas are identified by imaging, they can be removed while leaving the uterus intact—this decision of removing the uterusis a highly individualized issue. 

Associations

It is not uncommon for endometriosis and adenomyosis to coexist in the same patient. One study found that the prevalence of adenomyosis was significantly higher among women with endometriosis (13). The coexistence of these conditions may exacerbate symptoms and pose additional challenges in diagnosis and management (14).

Both endometriosis and adenomyosis have been linked to a variety of other health conditions, some of which include:

1. Chronic pelvic pain: Women with either endometriosis or adenomyosis may experience chronic pelvic pain, which can be debilitating and significantly impact daily life (15).

2. Uterine fibroids: Although they are distinct conditions, adenomyosis and uterine fibroids (leiomyomas) can coexist in the same patient, further complicating the diagnosis and treatment (16). 

3. Autoimmune and inflammatory diseases: Women with endometriosis have an increased risk of developing autoimmune and inflammatory disorders, such as rheumatoid arthritis, systemic lupus erythematosus, and inflammatory bowel disease (17). This association is less well-established for adenomyosis but has been suggested in some studies (18).

4. Mental health: Both endometriosis and adenomyosis have been linked to mental health issues, including depression, anxiety, and decreased quality of life due to chronic pain and infertility (19).

Research and Future Directions

There is a growing body of research focused on understanding the pathophysiology, diagnosis, and treatment of endometriosis and adenomyosis. Some key areas of interest include:

1. Biomarkers: Identifying specific biomarkers for endometriosis and adenomyosis could greatly improve the diagnostic process and allow for earlier intervention, potentially improving patient outcomes (20).

2. Non-invasive imaging techniques: The development of more accurate, non-invasive imaging techniques for diagnosing both endometriosis and adenomyosis is a priority for researchers, as this would reduce the need for invasive diagnostic procedures (21).

3. Novel treatment approaches: Researchers are exploring novel treatment approaches, such as targeted hormonal therapies, immunomodulators, and anti-inflammatory agents, to improve symptom management and fertility outcomes in both endometriosis and adenomyosis (22).

4. Genetic and epigenetic factors: Investigating the genetic and epigenetic factors that contribute to the development and progression of endometriosis and adenomyosis may lead to a better understanding of these conditions and inform future therapeutic strategies (23).

Get in touch with Dr. Steve Vasilev

More articles from Dr. Steve Vasilev:

Endometriosis And Menopause; Everything You Need To Know

How to tell the difference between endometriosis and ovarian cancer

What would happen to the signs and symptoms of endometriosis after menopause?

References

1. Vercellini P, Viganò P, Somigliana E, Fedele L. (2014). Endometriosis: pathogenesis and treatment. Nat Rev Endocrinol. 10(5): 261-75.
2. Parazzini F, Esposito G, Tozzi L, Noli S, Bianchi S. (2017). Epidemiology of endometriosis and its comorbidities. Eur J Obstet Gynecol Reprod Biol. 209: 3-7.
3. Zondervan KT, Becker CM, Koga K, Missmer SA, Taylor RN, Viganò P. (2018). Endometriosis. Nat Rev Dis Primers. 4(1): 9.
4. Giudice LC, Kao LC. (2004). Endometriosis. Lancet. 364(9447): 1789-99.
5. Vannuccini S, Tosti C, Carmona F, Huang SJ, Chapron C, Guo SW, Petraglia F. (2017). Pathogenesis of adenomyosis: an update on molecular mechanisms. Reprod Biomed Online. 35(5): 592-601.
6. Garcia L, Isaacson K. (2011). Adenomyosis: review of the literature. J Minim Invasive Gynecol. 18(4): 428-37.
7. Chapron C, Marcellin L, Borghese B, Santulli P. (2019). Rethinking mechanisms, diagnosis and management of endometriosis. Nat Rev Endocrinol. 15(11): 666-82.
8. Johnson NP, Hummelshoj L, Adamson GD, Keckstein J, Taylor HS, Abrao MS, et al. (2017). World Endometriosis Society consensus on the classification of endometriosis. Hum Reprod. 32(2): 315-24.
9. Champaneria R, Abedin P, Daniels J, Balogun M, Khan KS. (2010). Ultrasound scan and magnetic resonance imaging for the diagnosis of adenomyosis: systematic review comparing test accuracy. Acta Obstet Gynecol Scand. 89(11): 1374-84.
10. Vercellini P, Buggio L, Berlanda N, Barbara G, Somigliana E, Bosari S. (2016). Estrogen-progestins and progestins for the management of endometriosis. Fertil Steril. 106(7): 1552-71.e2.
11. Yeung P Jr, Sinervo K, Winer W, Albee RB Jr. (2011). Complete laparoscopic excision of endometriosis in teenagers: is postoperative hormonal suppression necessary? Fertil Steril. 95(6): 1909-12, 1912.e1.
12. García-Solares J, Donnez J, Donnez O, Dolmans MM. (2018). Pathogenesis of uterine adenomyosis: invagination or metaplasia? Fertil Steril. 109(3): 371-9.
13. Mijatovic V, Florijn E, Halim N, Schats R, Hompes P. (2010). Adenomyosis has no adverse effects on IVF/ICSI outcomes in women with endometriosis treated with long-term pituitary down-regulation before IVF/ICSI. Eur J Obstet Gynecol Reprod Biol. 151(1): 62-7.
14. Pinzauti S, Lazzeri L, Tosti C, Centini G, Orlandini C, Luisi S, et al. (2015). Coexistence of endometriosis and adenomyosis in women with chronic pelvic pain. J Obstet Gynaecol Res. 41(6): 909-14.
15. Howard FM. (2003). Chronic pelvic pain. Obstet Gynecol. 101(3): 594-611.
16. Stewart EA. (2015). Uterine fibroids. Lancet. 387(10022): 1189-99.
17. Sinaii N, Cleary SD, Ballweg ML, Nieman LK, Stratton P. (2002). High rates of autoimmune and endocrine disorders, fibromyalgia, chronic fatigue syndrome and atopic diseases among women with endometriosis: a survey analysis. Hum Reprod. 17(10): 2715-24.
18. Benagiano G, Brosens I, Habiba M. (2015). Structural and molecular features of the endomyometrium in endometriosis and adenomyosis. Hum Reprod Update. 21(4): 445-58.
19. Roomaney R, Kagee A. (2016). The association between pain, disability, fatigue and depression in women diagnosed with endometriosis: a moderated mediation analysis. J Psychosom Obstet Gynaecol. 37(4): 137-44.
20. Nisenblat V, Bossuyt PM, Shaikh R, Farquhar C, Jordan V, Scheffers CS, et al. (2016). Blood biomarkers for the non-invasive diagnosis of endometriosis. Cochrane Database Syst Rev. 5: CD012179.
21. Brosens I, Gordts S, Campo R, Benagiano G. (2016). Non-invasive methods of diagnosis of endometriosis. Curr Opin Obstet Gynecol. 28(4): 267-76.
22. Stratton P, Berkley KJ. (2011). Chronic pelvic pain and endometriosis: translational evidence of the relationship and implications. Hum Reprod Update. 17(3): 327-46.
23. Zondervan KT, Rahmioglu N, Morris AP, Nyholt DR, Montgomery GW, Becker CM, et al. (2016). Beyond endometriosis genome-wide association study: from genomics to phenomics to the patient. Semin Reprod Med. 34(4): 242-54.