Clinical characterization of endometriosis phenotypes

Endometriosis appears in various forms and symptoms. With regard to the established endometriosis classifications, it is hardly possible to draw conclusions from the endometriosis to the symptoms caused by it. The objective of this study was to evaluate whether different endometriosis phenotypes are associated with distinct pain profiles.

3329 patients underwent surgical treatment for endometriosis at the University Endometriosis Center Franconia of the Erlangen University between September 2011 and January 2024. They were grouped by phenotype [superficial (SE), deep (DIE) and adenomyosis (AM)] and assessed for pelvic pain, dyspareunia, dysuria and dyschezia. The study examined pain distribution across phenotypes and pain intensity among symptomatic patients (NRS > 0).

Patients with SE only reported pelvic pain less frequently and with lower intensity than those with additional AM Groups SE/AM and SE/DIE/AM. Dyspareunia was less common in Group SE only vs. Group SE/AM; pain intensity was highest in AM only and lowest in Group SE/DIE. Dysuria was most frequent in Group SE/DIE/AM, with no significant intensity differences. Dyschezia was more frequent in Group SE/DIE/AM and less in Group SE only, again without significant intensity differences.

Pain frequency and intensity differed by endometriosis phenotype. SE showed the lowest pain frequency and pelvic pain intensity. AM, especially with other subtypes, was linked to higher frequency and intensity of pelvic pain, as well as more dyspareunia and dysuria. DIE was mainly associated with more frequent dyschezia, but not with increased pelvic pain intensity.