The association of endosalpingiosis with chronic pelvic pain.

Background: Endosalpingiosis is a pathologic diagnosis of ectopic epithelium resembling the fallopian tubes. It has been described with clinical characteristics that are similar to endometriosis. The primary objective is to determine if endosalpingiosis (ES) has a similar association with chronic pelvic pain when compared to endometriosis (EM).

Methods: This is a retrospective case-control analysis of patients with a histologic diagnosis of endosalpingiosis or endometriosis at three affiliated academic hospitals between 2000 and 2020. All ES patients were included, and 1:1 matching was attempted to obtain a comparable EM cohort. Demographic and clinical data were obtained, and statistical analysis was performed.

Results: A total of 967 patients (515 ES and 452 EM) were included. ES patients were significantly older than EM patients (median age 52 vs. 48 years, P<0.001), but other demographic variables were similar. Fewer ES patients had baseline chronic pelvic pain than EM patients (25.3% vs. 47%, P<0.001), and patients with ES were less likely to undergo surgery for the primary indication of pelvic pain (16.1% vs. 35.4%, P<0.001). Pelvic pain as the surgical indication remained lower in the ES group in multivariable analysis (OR=0.49, P<0.001). There were similar rates of persistent postoperative pain between ES and EM groups (10.1% vs. 13.5%, P=0.109).

Conclusions: Although endosalpingiosis can be associated with chronic pelvic pain, the incidence of pain is significantly lower than in patients who have endometriosis. These findings suggest that ES is a unique condition that differs from EM. Further research including long-term follow-up and patient-reported outcomes is imperative.