New aspects of the etiology and pathogenesis of endometriosis

Background: Endometriosis is one of the most common benign diseases in the field of gynecology; however, after years of extensive research the pathogenesis remains enigmatic. State of research: It is known that increased retrograde menstruation caused by uterine dysperistalsis and hyperpersistalsis and subsequent increased oxidative stress on the peritoneal mesothelium are vital factors facilitating the implantation of disseminated endometrial cells and endometriotic lesion formation. The eutopic endometrium in endometriosis patients appears to have a differential protein expression when compared to controls and ectopic endometrial cells of endometriotic lesions exhibit an altered potential for adhesion, invasion and proliferation. The capability for local estrogen biosynthesis and relative progesterone resistance as well as recently demonstrated epigenetic alterations of endometrial cells are key features for the development of this disease. Endometriosis is associated with an immunological dysfunction. Impaired immunosurveillance and peritoneal clearance on the one hand and the proinflammatory microenvironment on the other hand are considered to be key factors for the development of endometriotic lesions. Perspectives: Recent data indicate the relevance of endometrial stem cells in the etiology and pathogenesis of endometriosis. Due to the high proliferative potential, extended cell differentiation capacity and tremendous ability for regeneration, endometrial stem cells are in the focus of research activities. © 2015, Springer-Verlag Berlin Heidelberg.