Back to the Original Question in Endometriosis: Implantation or Metaplasia?

Abstract

The pathogenesis of some forms of endometriosis is still controversial. Different research approaches have been used to clarify this issue and an intense debate has derived over the years among scientists. This paper presents and discusses aged and modern ideas derived from various observations in different research areas on this specific topic. More specifically, data derived from histological results, animal studies, anatomical findings and basic research activity are presented. Although an increasing body of evidence tends to support the implantation theory, which currently represents the most recognized pathogenic model for endometriosis, some aspects of this disease remain obscure and the scientific and medical communities have still not made significant progress in terms of completely elucidating the histogenesis of some forms of the disease.