Chronic lower abdominal or pelvic pain can be very frustrating, especially when the root cause seems to be an enigma to every physician you see. Often, patients with chronic pelvic or abdominal pain find themselves being referred from one physician to another over several years with nothing to show for it other than frustratingly negative studies and tests. Due to the limitations of modern medicine and an amalgam of other factors, endometriosis is a common condition in reproductive-aged patients and adolescents that is frequently overlooked as a possible cause of these symptoms.
What is endometriosis?
Endometriosis is tissue that resembles the endometrium lining (the inside of the uterus), but which is found outside the uterus where it doesn’t belong. It can cause any of a myriad of symptoms—including abdominal cramping, pelvic pain, pain during intercourse, burning with urination, constipation, fatigue, or infertility—or none at all. (1-3)
The condition is estimated to affect 10% of reproductive aged women, and rates of those affected by the condition is believed to be even higher for those experiencing infertility or persistent pelvic pain which is estimated to be up to be up to 75%. (4) Of those with endometriosis, 30% experience pelvic or lower abdominal pain that does not respond to treatment, which extrapolates to 60 million globally. (4, 5)
Endometriosis can be classified into 3 main types:
● Superficial peritoneal endometriosis: endometrial tissue located outside of the uterus that has burrowed less than 5mm deep into peritoneal (abdominal cavity) or organ (can include ligaments, bowel, bladder, ureters, etc) tissue. This is the most common variation.
● Deep infiltrating endometriosis (DIE): endometrial tissue that has implanted 5mm or deeper into peritoneal or organ tissue.
● Endometriomas (or chocolate cysts): endometrial tissue that has implanted onto the ovaries.
Why is endometriosis so difficult to diagnose?
Endometriosis is elusive due to many compounding factors.
● Presentation of symptoms often differs. Some patients may have severe cases of endometriosis with little to no symptoms, while some may have mild superficial endometriosis with severe pain. (6)
● Endometriosis can be coexisting with other conditions such as IBS, fibroids, fibromyalgia, IBD, and even some cancers, which can mislead physicians into attributing your symptoms to these other conditions due to a lack of awareness of endometriosis. (7) This along with a wide range of possible, but not definite symptoms, renders symptom-based diagnosis difficult for physicians that do not specialize in the disease.
● No labs or radiology studies have been proven sufficient to rule out or diagnose the condition.
So, what does my negative MRI or ultrasound mean? Where do I go from here?
With regards to endometriosis, imaging is not an effective diagnostic tool. Abdominal MRIs and ultrasounds are not sufficient to visualize endometriosis. (8) Transvaginal and transrectal ultrasounds and pelvic MRIs have little use in identifying superficial endometriosis—which is in fact the most common manifestation of the disease. (9) While some studies published show that pelvic MRIs may possibly help in identifying the less common deep infiltrating endometriosis (DIE) or endometriomas, these studies have yet to have been sufficient and of high enough quality to reach any meaningful conclusions. (9) One small 2018 study showed a sensitivity of 90% and specificity of 66% of the pelvic MRI for the rarer DIE. (10) This means that even for DIE lesions, roughly 10% of cases were not detected by the pelvic MRI and 33% of endometrial cases may not be specifically determined to be DIE. It is also important to note that the MRI’s effectiveness in sensing DIE varies based on location of the endometrial lesion, meaning that the MRI may be less effective at sensing endometriosis in some parts of the pelvis. (10) Subsequently, minimally-invasive laparoscopic or robotic surgery remains the gold standard for diagnosis and excision endometriosis. (9)
Despite negative radiology studies such as a negative pelvic MRI, endometriosis may still be a contributing factor to your pelvic pain and array of symptoms. Arrange a consult with your local endometriosis specialist for an evaluation and to discuss possible treatment options.
Schedule an appointment with CEAPS online, by email at firstname.lastname@example.org, or over the phone by calling (703) 505-0444.
1) Gallagher JS, DiVasta AD, Vitonis AF, Sarda V, Laufer MR, Missmer SA. The impact of endometriosis on quality of life in adolescents. J Adolesc Health 2018;63: 766-72.
2) Nnoaham KE, Hummelshoj L, Webster P, et al. Impact of endometriosis on quality of life and work productivity: a multicenter study across ten countries. Fertil Steril 2011; 96(2): 366.e8-373.e8.
3) Rush G, Misajon R, Hunter JA, Gardner J, O’Brien KS. The relationship between endometriosis-related pelvic pain and symptom frequency, and subjective well being. Health Qual Life Outcomes 2019; 17: 123.
4) Shafrir AL, Farland LV, Shah DK, et al. Risk for and consequences of endometriosis: a critical epidemiologic review. Best Pract Res Clin Obstet Gynaecol 2018;51:1-15.
5) Caumo W, Deitos A, Carvalho S, et al. Motor cortex excitability and BDNF levels in chronic musculoskeletal pain according to structural pathology. Front Hum Neurosci 2016; 10: 357.
6) Johnson NP, Hummelshoj L, Adamson GD, et al. World Endometriosis Society consensus on the classification of en-dometriosis. Hum Reprod 2017;32:315-24.
7) Ballard KD, Seaman HE, de Vries CS, Wright JT. Can symptomatology help in the diagnosis of endometriosis? Findings from a national case-control study. BJOG 2008; 115: 1382-91.
8) Bazot M, Lafont C, Rouzier R, Roseau G, Thomassin-Naggara I, Daraï E. Diagnostic accuracy of physical examination, transvaginal sonography, rectal endoscopic sonography, and magnetic resonance imaging to diagnose deep infiltrating endometriosis. Fertil Steril. 2009;92(6):1825-1833.
9) Nisenblat V, Bossuyt PMM, Farquhar C, Johnson N, Hull ML. Imaging modalities for the non-invasive diagnosis of endometriosis. Cochrane Database Syst Rev 2016; 2: CD009591.
10) Alborzi S, Rasekhi A, Shomali Z, et al. Diagnostic accuracy of magnetic resonance imaging, transvaginal, and transrectal ultrasonography in deep infiltrating endometriosis. Medicine (Baltimore). 2018;97(8):e9536.