Microanatomy and function of the eutopic endometrium in women with endometriosis

Endometriosis is a disease that still presents many puzzles to clinicians and basic research scientists. Until recently, it has been regarded as a condition that arises when normal endometrium adheres to the peritoneal surface and then grows into an 'inflammatory lesion, which adversely influences local reproductive tract function and causes pain. It is now becoming clear that the endometrium within the uterus in these women differs significantly in function from 'normal, and that these anomalies probably precede the development of classical ectopic endometriotic lesions. However, the etiology and mechanisms by which endometriosis arises are still far from certain. This review attempts to address the extensive, but fragmented, evidence that demonstrates widespread molecular disturbances in endometrial function and microstructure underlying this complex condition. The review also addresses some of the novel concepts that are being raised by these exciting new discoveries.