SDC1 and endometriosis: Using the archival full-thickness eutopic endometrial tissues obtained from premenopausal women undergoing hysterectomy due to benign uterine corpus disorders (fibroids, adenomyosis, endometriosis) and benign ovarian tumors, we first investigated the prevalence of CE in the histopathologic CE (defined as five or more CD138(+) ESPCs in 10 microscopic high power fields (HPFs), 400-fold magnification) in 2011.