Approach

Although no single symptom or finding is diagnostic, clinical suspicion for endometriosis is generally sufficient for presumptive diagnosis.[4] 

Clinical evaluation

A history of painful menstrual cramps (dysmenorrhea), especially if unrelieved by nonsteroidal anti-inflammatories (NSAIDs), is fairly suggestive of the diagnosis.[13] Primary dysmenorrhea (menstrual cramps that occur in the absence of obvious pelvic pathology) is extremely common in younger women.[1] Pain characterized as progressively worsening and continuous, however, is most characteristic for women with endometriosis.

Women may present with a spectrum of symptoms, including various genitourinary (e.g., dysuria, flank pain, hematuria) and gastrointestinal (e.g., dyschezia, hematochezia) complaints.[17][31] Commonly, women may also describe deep dyspareunia or pain on deep penetration during intercourse.[5] The diagnosis should also be considered in women presenting with unexplained subfertility.[33]​ Endometriosis is present in up to 40% of women presenting with unexplained subfertility.[33]​ These women may otherwise be asymptomatic.

Several demographic and anthropometric measures such as white ethnicity, low body mass index, and social behaviors (late first sexual encounters, smoking) have been weakly associated with endometriosis.[11][18]

Depression and anxiety appear to be associated with endometriosis, especially if chronic pain is present.[34][35] Therefore, women presenting with endometriosis should be assessed for comorbid mood or anxiety disorders. A multisystem approach that considers physical and psychological perspectives is required. See Depression in adults and Generalized anxiety disorder.

Enquire about a possible family history of endometriosis, as well as whether the woman misses work or school because of debilitating pain. Having a first-degree relative with a history of endometriosis increases the likelihood of endometriosis.[36] Absenteeism from work or school, along with a positive family history of endometriosis, is strongly correlated with a diagnosis of endometriosis.[37]

A gentle and thorough exam may help distinguish endometriosis from other pelvic pain disorders. Single digit pelvic exam, followed by bimanual and rectovaginal exams may reveal pelvic mass (ovarian endometrioma), fixed and retroverted uterus or uterosacral ligament nodularity and tenderness.[17] Inspection and palpation of the abdomen is also recommended.[17][36] Clinical exam may be normal in women with endometriosis.[17][36]​ Physical exam should be decided on a case-by-case basis, and with informed patient consent. The National Institute for Health and Care Excellence (NICE) in the UK recommends that an abdominal exam should still be offered (to exclude abdominal masses) if a pelvic exam is declined or is unsuitable.[36]

Ancillary studies

Transvaginal ultrasound is the imaging modality of choice to assess for the presence of endometriosis.​[36][38]​​​​ Transvaginal ultrasound may not detect early disease. Sensitivity and specificity for detecting endometriomas is 93% and 96%, respectively.[39][Figure caption and citation for the preceding image starts]: Ultrasound of ovarian endometriomaFrom the collection of Dr Jonathon Solnik; used with permission [Citation ends].com.bmj.content.model.Caption@27fa29f7

Transvaginal ultrasound has high specificity, but limited sensitivity, for diagnosis of vaginal, bladder, parametrium, rectovaginal septum, and uterosacral ligament endometriosis.[40][41][42][43] For the diagnosis of rectosigmoid deep endometriosis, the specificity is 97% and the sensitivity is 89%.[44] Rectal endoscopic ultrasound may be considered in women with suspected deep pelvic endometriosis or involvement of the colon/rectum, as this may help plan surgical resection.[39]

The “sliding sign” can be used to assess for posterior cul-de-sac obliteration. A negative sliding sign is documented when the rectosigmoid colon does not slide smoothly over the posterior uterus/cervix. A negative sliding sign is both sensitive and specific for deep endometriosis and posterior cul-de-sac obliteration.[45]

In the UK, NICE recommends that additional investigations and referral (if necessary) should be carried out concurrently, and alongside starting initial pharmacologic management.[36]​ This is to reduce delays in diagnosis.[36]​ They recommend that all patients with suspected endometriosis should be offered a transvaginal ultrasound (organized by the patient’s general practice), even if the physical exam is normal.[36]​ If a transvaginal ultrasound is unsuitable or declined by the patient, NICE recommends that a transabdominal ultrasound of the pelvis should be considered.[36]​ They noted that although there was much less evidence on the transabdominal approach versus transvaginal, it was still necessary to provide an alternative option for when the latter is declined or unsuitable.[36]​ The transvaginal ultrasound is used to:[36]

  • Identify ovarian endometriomas and deep endometriosis (including that involving the bowel, bladder or ureter)

  • Identify or rule out alternative pathologies

  • Guide management and enable referral to an appropriate service. Note that a normal ultrasound scan does not exclude endometriosis and referral may still be appropriate.

Magnetic resonance imaging (MRI) may be considered in selected patients.[17][36]​ MRI can detect extra-pelvic and rectovaginal implants. MRI (or specialist transvaginal ultrasound) may be used to diagnose and assess the extent of deep endometriosis.[17][36]​ NICE advises that these scans should be planned and interpreted by a professional with specialist expertise in gynecologic imaging.[36][Figure caption and citation for the preceding image starts]: MRI - fibrotic nodules involving the uterosacral ligaments and rectal wallBazot M, et al. Radiology. 2004 Aug;232(2):379-89; used with permission [Citation ends].com.bmj.content.model.Caption@13ed7c0e

MRI, 3D ultrasonography, or hysterosalpingography are ideal for imaging women with mullerian anomalies (e.g., transverse vaginal septum) or for identifying any scarring or tubal blockage causing outflow tract obstruction (e.g., in those with subfertility).

MRI or specialist pelvic ultrasound may also be used prior to operative laparoscopy in patients with suspected deep endometriosis.[36]

Normal imaging (e.g., ultrasound, MRI) does not exclude endometriosis.[36]

Serological markers such as CA-125 lack specificity and have not been shown to be useful diagnostic tools, while studies for other biomarkers are ongoing.[46][47]

NICE recommends referring patients to gynaecology for further investigation and management if they have any of the following:[36]

  • symptoms of endometriosis which have a detrimental impact on their daily functioning or which are persistent or recurrent

  • pelvic signs of endometriosis (without suspected deep endometriosis)

  • suspected or confirmed endometrioma, deep endometriosis, or endometriosis outside the pelvic cavity. These patients should be referred to a specialist endometriosis service.

NICE recommends referring patients ages under 18 with suspected or confirmed endometriosis to a pediatric and adolescent gynecology service or specialist endometriosis service.[36]

Surgical findings

Surgical inspection with histopathologic confirmation remains the definitive test for diagnosis, although a negative histologic result does not exclude endometriosis, and up to 50% of peritoneal biopsies obtained during laparoscopy for pelvic pain show no evidence of disease.[36][48]​ The use of preoperative imaging is associated with decreased morbidity and mortality and can aid patient decision making, surgical planning, and management.[49]​ Symptom severity may not correlate with the extent of disease seen on careful surgical inspection. Not all women require surgical investigation. However, some physicians feel that if first line medical treatments (oral contraceptive pills, NSAIDs) fail, or if signs and symptoms are highly suspicious for endometriosis at initial evaluation, proceeding to surgery is an appropriate early measure. Diagnostic laparoscopy may be considered for suspected endometriosis even if other investigations (e.g., imaging) have been normal.[36]

Laparoscopic evaluation is the preferred approach given the shorter recovery time compared with exploratory laparotomy. Surgical treatment can be simultaneously performed (with prior patient consent).[36]​ 

Operative findings widely vary and women should be staged according to the extent and type of lesions; size and depth of peritoneal/ovarian implants; and presence and extent of pelvic adhesions and degree of cul-de-sac obliteration.[50]

  • Early stage (minimal to mild) is marked by superficial peritoneal implants which appear vesicle-like (clear or red). These can be isolated or scattered and are more common in adolescents.

  • Moderate disease is typically characterized by multiple superficial or deep lesions with a variable degree of adhesions.

  • Advanced disease is typified by multiple implants (deep and fibrotic), parametrial or retroperitoneal extension, ovarian endometrioma, an obliterated cul-de-sac and pelvic adhesions.[Figure caption and citation for the preceding image starts]: Laparoscopic image of ovarian endometriomaFrom the collection of Dr Jonathon Solnik; used with permission [Citation ends].com.bmj.content.model.Caption@37e884c8

Use of this content is subject to our disclaimer