[Frontiers in Bioscience E4, 2754-2763, June 1, 2012]

Stem cell theory for the pathogenesis of endometriosis

Tetsuo Maruyama1, Yasunori Yoshimura1

1Department of Obstetrics and Gynecology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Conventional theories
3.1. Implantation theory
3.1.1. Retrograde menstruation theory
3.1.2. Lymphatic and vascular metastasis theory
3.1.3. Iatrogenic direct implantation
3.2. Metaplasia theory
3.2.1. Coelomic metaplasia theory
3.2.2. Embryonic rest theory
3.3. Induction theory
3.4. Composite theory
4. Stem cell theory
4.1. Adult stem cells and human endometrium
4.2. Endometrial stem/progenitor cells and their roles in endometrial physiology
4.3. Possible role of stem/progenitor cells in the pathogenesis of endometriosis
5. Summary and perspective
6. Acknowledgements
7. References

1. ABSTRACT

Proposed hypothetical causes of endometriosis include retrograde menstruation, lymphatic and vascular metastasis, iatrogenic direct implantation, coelomic metaplasia, embryonic rest, and mesenchymal cell differentiation (induction). Each theory, individually, fails to account for all types of endometriotic lesions, thereby implicating combined and/or type-specific mechanisms. Recent evidence supports the presence of endometrial stem/progenitor cells and their possible involvement in eutopic endometrial regeneration and differentiation. Thus an additional novel mechanism for the origin of endometriotic lesions is that they arise from ectopic endometrial stem/progenitor cells.