Endometriosis: diagnosis and management

Ultrasound

There was evidence that transvaginal ultrasound was, in the majority of studies, moderately to highly sensitive at detecting deep endometriosis, particularly when involving the ovaries. However, the committee were aware that these data were when the ultrasound was carried out by a specialist operator, and that ultrasounds carried out in a non-specialist setting may not achieve this degree of sensitivity. The committee also agreed, however, that non-specialist ultrasound was still a useful tool that would help identify deep endometriosis or endometrioma or other pathology. They therefore recommended that all women or people with suspected endometriosis should have an ultrasound examination as this will allow identification of ovarian endometriomas or deep endometriosis, may identify other pathology which could be leading to the symptoms (such as fibroids or malignancy), and will help determine the need for a referral and the most appropriate referral option. The committee agreed that an ultrasound should be offered to all women or people presenting with symptoms suggesting endometriosis as part of the standard diagnostic work-up, as failure to diagnose endometriosis was a common problem.

The recommendation on alternatives to transvaginal ultrasound has been amended to clarify that the reasons for not carrying out a transvaginal ultrasound may be because the woman or person with suspected endometriosis does not wish to have this internal scan, or if there are other reasons which mean it is not suitable for the person. This clarifies that it is not just the healthcare professional who makes a decision on the use of a transvaginal ultrasound.

Based on the committee's knowledge and experience, the recommendation on referral to a gynaecology service after ultrasound has been updated to 'refer' instead of 'consider referring' as in the previous version of this guideline, as the committee agreed that there was no other option but to refer people who met the listed criteria for referral so that they can receive appropriate further investigations and treatment. People would still have the option to decline the referral. In addition, the criteria for referral to a specialist endometriosis service were amended to include the presence of an endometrioma and the location of deep endometriosis has been clarified. Endometriomas are often associated with deep endometriosis or severe endometriosis, and management, particularly if fertility is a priority, can be complicated so specialist services are most appropriate for this. The recommendation on referral of young women or people has similarly also been updated.

Serum CA125

There was some new evidence for the sensitivity and specificity of CA125 to diagnose endometriosis, but the committee agreed that this was insufficient to change the existing recommendation which advised that it was not a suitable tool to diagnose endometriosis.

MRI

There was evidence from the majority of studies that MRI was moderately to highly sensitive at detecting deep endometriosis. The evidence for the use of transvaginal ultrasound for the diagnosis of deep endometriosis involving a number of locations (vaginal, rectosigmoid, rectovaginal, uterosacral ligaments, pouch of Douglas, bowel, bladder and ureters) showed that, in the majority of studies, it was moderately sensitive, although the committee agreed this may depend on operator experience, and that sensitivity would be optimal with more experienced operators who would be likely to be carrying out ultrasounds in gynaecology or specialist endometriosis services. Based on this, the committee agreed that suspected deep endometriosis could be diagnosed and assessed by specialist ultrasound or MRI, and the choice of imaging technique should be a clinical decision based on available resources.

The committee agreed, based on their knowledge and experience, that both specialist ultrasound and MRI scans should be both planned and interpreted by someone with expertise in gynaecological imaging to maximise diagnostic accuracy.

Diagnostic laparoscopy

The committee agreed that laparoscopy (which had been considered the gold standard diagnostic technique in the evidence review) could be used as an option for women or people with symptoms of endometriosis even if ultrasound or MRI results were normal. The committee noted, based on their knowledge and experience, there was a need to ensure the imaging results were recorded when carrying out a diagnostic laparoscopy.

The committee noted that even a normal laparoscopy could not rule out endometriosis fully, as there was a possibility of microscopic endometriosis causing the symptoms. The committee therefore updated the existing recommendation and clarified that management of symptoms was the aim of treatment.

Ultrasound

Early investigation using ultrasound reflects what is now current best practice but it is possible there will be some increase in the use of early transvaginal ultrasound. An early ultrasound scan may replace the need for a transvaginal ultrasound scan after referral to gynaecology services for some women or people (particularly those who are referred and then seen without undue delay), and so is unlikely to greatly increase the total number of transvaginal ultrasounds for diagnosis of endometriosis. This change is therefore not expected to lead to a large increase in resource use in terms of the number of ultrasound scans, but there will be a need for additional training of sonographers to increase their competency to detect features associated with endometriosis.

The change to referring all women and people with symptoms of, or confirmed endometriosis who meet the specified criteria, compared to considering referral in the previous version of this guideline may lead to more people being referred, but this will improve the diagnosis and management of endometriosis, and is likely to lead to earlier diagnosis and treatment and less damage to organs and structures from the disease, and therefore reduce subsequent treatment costs.

MRI

The use of specialist ultrasound as an alternative to MRI to diagnose deep endometriosis may lead to cost-savings in the NHS, as MRI is more expensive than ultrasound. The specialist planning and interpretation of scans may increase the number of people whose endometriosis is successfully identified.

Serum CA125 and diagnostic laparascopy

These recommendations reinforce current practice.

Return to recommendations