Evaluation of the association between self-reported pre-operative symptoms with surgically diagnosed endometriosis using the #ENZIAN classification in a multi-centre cohort.

STUDY QUESTION Is there an association between pre-operative symptoms and intraoperatively described localization and size of endometriosis lesions as assessed by the #ENZIAN classification system? SUMMARY ANSWER Dyschezia is associated with any deep infiltrating endometriosis (DE) lesions; severe dyspareunia is associated with adenomyosis. WHAT IS KNOWN ALREADY Previous attempts to correlate the common symptoms of endometriosis to the size and localization of lesions have been of moderate success. STUDY DESIGN, SIZE, DURATION This prospective, multicentre, non-interventional cross-sectional study was conducted between September 2022 and January 2024 at 18 endometriosis centres in Austria, Germany, and Switzerland, enrolling a total of 838 patients with endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS The study included 521 patients with complete information on pre-operative symptoms and intraoperatively diagnosed endometriosis classified by the #ENZIAN classification system. Associations between symptoms and localization of endometriosis lesions were analysed. MAIN RESULTS AND THE ROLE OF CHANCE Nearly all patients (n = 513) (98.5%) suffered from dysmenorrhea whereas 294 (56.4%), 208 (39.9%), and 102 (19.6%) patients reported dyspareunia, dyschezia, and dysuria, respectively. Dyspareunia rated as ≥8 on a visual analogue scale was reported 3.5-fold more often in patients with adenomyosis only (OR 3.56 [1.38-9.17]) than in those without, while dyschezia was almost twice as likely in those with any form of DE (OR 1.86 [1.3-2.65]). LIMITATIONS, REASONS FOR CAUTION A larger study population is needed to clinically define relevant sub-groups based on localization of lesions. WIDER IMPLICATIONS OF THE FINDINGS The findings of the present study identify adenomyosis as a strong driver of pain, especially dyspareunia, making awareness of its high prevalence of utmost importance. Few direct associations between symptoms and lesions were identified. Endometriosis-related symptoms, especially when chronic, are multi-factorial and cannot be readily correlated to specific lesion sites. STUDY FUNDING/COMPETING INTEREST(S) This study received no external funding and all the authors declare they have no conflicts of interest pertaining to this study. TRIAL REGISTRATION NUMBER Clinical Trials NCT05624567.