[Endometriosis: physiopathology and investigation trends (first part)]

Until today endometriosis continues to be a diagnostic challenge since the only way to confirm a diagnosis, based on clinical criteria, is through direct visualization of the endometriosis lesions. This has a direct impact in the development of proper statistics on the incidence and prevalence of endometriosis. Current research has been focused on the basis of the Retrograde Menstruation theory, establishing the involvement of various biochemical, immunologic and molecular factors within the physiopathology of endometriosis. The development of endometriosis has been divided into 5 basic processes: adhesion, invasion, recruiting, angiogenesis and proliferation, here, we have revised the first two due to the importance they potentially contain with regards to diagnosis and therapy. Research on adhesion has led to studies on the peritoneal epithelium structure, the role of integrins, intercellular adhesion molecules (ICAM), cadherins and hyaluronic acid; invasiveness has led to the study of the tumor necrosis factor alpha (TNF-alpha), various protocols on metaloproteinases and their inhibitors as well as their interactions and response to sexual steroids, tumor growth factor beta (TGF-beta), interleukins and metalloproteinase polymorphisms. These advances have been crucial, though various observations leads us to believe that the etiology is multifactorial, there are factors whose antagonists, inhibitors or suppressors may actually have a role as molecular markers or therapeutic agents of endometriosis.