Higher prevalence of chronic endometritis in women with endometriosis: a possible etiopathogenetic link

Objective: To evaluate the association between endometriosis end chronic endometritis (CE) diagnosed by hysteroscopy, conventional histology, and immunohistochemistry. Design: Case-control study. Setting: University hospital. Patient(s): Women with and without endometriosis who have undergone hysterectomy. Intervention(s): Retrospective evaluation of 78 women who have undergone hysterectomy and were affected by endometriosis and 78 women without endometriosis. Main outcome measure(s): CE diagnosed based on conventional histology and immunohistochemistry with anti-syndecan-1 antibodies to identify CD138 cells. Result(s): The prevalence of CE was statistically significantly higher in the women with endometriosis as compared with the women who did not have endometriosis (33 of 78, 42.3% vs. 12 of 78, 15.4% according to hysteroscopy; and 30 of 78, 38.5% vs. 11 of 78, 14.1% according to histology). The women were divided into two groups, 115 patients without CE and 41 patients with CE. With univariate analysis, parity was associated with a lower risk for CE, and endometriosis was associated with a statistically significantly elevated risk of CE. Using multivariate analysis, parity continued to be associated with a lower incidence of CE, whereas endometriosis was associated with a 2.7 fold higher risk. Conclusion(s): The diagnosis of CE is more frequent in women with endometriosis. Although no etiologic relationships between CE and endometriosis can be established, this study suggests that CE should be considered and if necessary ruled out in women with endometriosis, particularly if they have abnormal uterine bleeding. Identification and appropriate treatment of CE may avoid unnecessary surgery.