Reassessment of prevalence of tubal endometriosis, and its associated clinicopathologic features and risk factors in premenopausal women received salpingectomy

INTRODUCTION: To reassess the prevalence of fallopian tube endometriosis (EM), and its associated clinicopathologic characteristics and risk factors. METHODS: Cross-sectional study was conducted from June 2016 to August 2017. Unpregnant premenopausal women who underwent unilateral or bilateral salpingectomy due to gynecologic diseases were recruited. Patient clinical data and fallopian tube specimens were collected. Hematoxylin-eosin (H&E) staining and CD10 immunohistochemistry were used to diagnose tubal EM. RESULTS: Tubal EM prevalence was 14.48% (161/1112, 95% confidence interval [CI] 12.41%–16.55%). Prevalence of tubal EM in patients with EM was 37.37% (95%CI 30.58%–44.17%) which is higher in patients without EM (9.52%, 95%CI 7.61%–11.42%) and even higher in those with multi-organ EM (43.94%, 95%CI 35.36%–52.52%). At unilateral or bilateral salpingectomy, tubal EM was more likely located in the left fallopian tube (52.17%) than the right one (40.37%) and presence of hydrosalpinx/ hematosalpinx increased in women with tubal EM than without tubal EM (43.47% versus 23.79%). With increasing severity of pelvic EM (r = 0.26, P<10(−4)) and adhesion (r = 0.25, P<10(−4)), the tubal EM prevalence also increased. Pathological examination found that tubal EM was more likely located in the mucosa of the proximal tube with significantly more surrounding inflammation and fibrotic lesions than the serosa/sub-serosa in the distal tube (r = 0.90, P<10(−4)). Multivariate analysis showed that abnormal uterine bleeding (AUB) (AOR = 3.10), previous EM surgery (AOR = 4.22) and tubal ligation (AOR = 2.33) were risk factors for tubal EM. CONCLUSIONS: These data provide clinicians with important information that the prevalence of tubal EM among premenopausal unpregnant patients was higher than previous investigators, especially higher among women with EM diseases. Identifying its clinicopathologic characteristics and predictors may facilitate clinical decision making.