{"paper_id":"1f583059-ab47-4c50-a562-5a288a53f4d4","body_text":"Abstract\nEndometriosis is a chronic disease characterized by endometrial tissue located outside of the uterine cavity and is associated with chronic pelvic pain and infertility. However, an in-depth understanding of the pathophysiology of endometriosis is still elusive. Once generated within pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by innate immune system in pelvic microenvironment by their interaction with endometrial cells and immune cells. We conducted a series of studies in perspectives of pelvic inflammation that is triggered primarily by bacterial endotoxin (lipopolysaccharide, LPS) and is mediated by Toll-like receptor 4 (TLR4) and showed their involvement in the growth regulation of visible peritoneal endometriosis. Even with the careful eye of an expert surgeon, we may sometimes miss to detect peritoneal lesion within peritoneal cavity or deep into peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as invisible endometriosis. Here, we discuss the color appearance of peritoneal lesions, role of innate immune system in visible endometriosis, and finally our recent findings on invisible microscopic endometriosis and their biological and clinical significance.\nAccess this chapter\nTax calculation will be finalised at checkout\nPurchases are for personal use only\nSimilar content being viewed by others\nReferences\nStrathy JH, Molgaard CA, Coulman CB. Endometriosis and infertility: a laparoscopic study of endometriosis among fertile and infertile women. Fertil Steril. 1982;38:667–72.\nSampson J. Peritoneal endometriosis due to menstrual dissemination of endometrial tissue into the peritoneal cavity. Am J Obstet Gynecol. 1927;14:422–9.\nThomas EJ, Prentice A. The etiology and pathogenesis of endometriosis. Reprod Med Rev. 1992;1:21–36.\nNisolle M, Casanas-Rouz F, Donnez J. Immunohistochemical analysis of proliferative activity and steroid receptor expression in peritoneal and ovarian endometriosis. 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J Reprod Med. 1988;33:915–20.\nAcknowledgement\nI gratefully thank Dr. Michio Kitajima of Nagasaki University Hospital and Dr. Akira Fujishita of Saiseikai Nagasaki Hospital for their kind assistance in sample collection; Prof. Masahiro Nakashima of Atomic Bomb Disease Institute, Nagasaki for his experimental advice; and Prof. Hideaki Masuzaki of Nagasaki University Hospital for reading/advice.\nAuthor information\nAuthors and Affiliations\nCorresponding author\nEditor information\nEditors and Affiliations\nRights and permissions\nCopyright information\n© 2014 Springer Japan\nAbout this chapter\nCite this chapter\nKhan, K.N. (2014). Visible and Invisible (Occult) Endometriosis. In: Harada, T. (eds) Endometriosis. Springer, Tokyo. https://doi.org/10.1007/978-4-431-54421-0_3\nDownload citation\nDOI: https://doi.org/10.1007/978-4-431-54421-0_3\nPublished:\nPublisher Name: Springer, Tokyo\nPrint ISBN: 978-4-431-54420-3\nOnline ISBN: 978-4-431-54421-0\neBook Packages: MedicineMedicine (R0)","source_license":"CC0","license_restricted":false}