Editor's Formulation

This issue on endometriosis has six chapters on basic science, three on diagnosis, and five on treatment. These chapters review long-controversial issues in endometriosis, new data, and stimulating theories; they also describe creative approaches to clinical management. Drs. Craig Witz and Robert Schenken have reviewed in detail the multiple theories formulated to explain the presence of endometriosis, namely implantation; mechanical transplantation; lymphatic and vascular metastasis; and direct extension, uterotubal, coelomic metaplasia, induction, embryonic rest, and composite theories. Clearly, the fact there are so many theories underlines our lack of understanding and the complexity of this condition. It is, however, promising that basic research into peritoneal fluid leukocytes, macrophage and cytokine production, natural killer cells, and steroid receptors described in this chapter are revealing mechanisms which raise many questions but also are gradually uniting the hypotheses into a coherent whole. It seems likely that genetic, mechanical, biochemical, hormonal, and immunologic factors have complex interrelationships which enable endometriosis to develop in some women and not in others.