Intramedullary Endometriosis of the Conus Medullaris

In Reply: Despite decades of research, the pathogenesis of endometriosis remains poorly understood (). It has been proposed that different types of endometriotic lesions are likely to have discrete etiologies (). It is not necessary that ectopic endometrial tissues originate from primary endometrial tissue () and endometriosis is also reported in posthysterectomy patients (). Endometriosis appears in patients without endometrial tissue, including those with Turner syndrome or uterine hypoplasia, or in the male bladder, prostate, and testis. This means ectopic endometria tissue may be from coelomic metaplasia rather than primary endometrial tissue (). However, the most widely accepted theory proposes retrograde menstruation, implantation, and proliferation and differentiation of endometrial tissue, as well as invasion of the underlying tissue (). As suggested by Batt et al. in their Letter to the Editor, an alternative theory is that endometriosis results from metaplasia of müllerian-type epithelium, by which cellular modification owing to epigenetic or genetic alterations results in transformation of a specific müllerian tissue type into endometrial tissue (). Müllerianosis is a term used to indicate lesions composed of an admixture of two or three types of müllerian-derivation glands in heterotopic sites and at histological examination lesions in müllerianosis are composed of endocervical, endometrial and tubal glands within a smooth muscle nodule (). We cannot totally disagree with the authors; however, because our patient had only endometrial tissue, it is difficult to justify term intramedullary müllerianosis of the conus medullaris in our case (). Amit AgrawalDharan, Nepal Bellore J.P. ShettyJagadeesh H. MakannavarLathika ShettyJayaprakash ShettyVikram ShettyMangalore, India - 1. Agrawal A, Shetty BJ, Makannavar JH, Shetty L, Shetty J, Shetty V: Intramedullary endometriosis of the conus medullaris: Case report. Neurosurgery 59:E428, 2006. - 2. Barresi V, Cerasoli S, Vitarelli E, Donati R: Spinal intradural mullerianosis: A case report. Histol Histopathol 21:1111–1114, 2006. - 3. Fujii S: Secondary Müllerian system and endometriosis. Am J Obstet Gynecol 165:219–225,1991. - 4. Lim S, Kim JY, Park K, Kim BR, Ahn G: Mullerianosis of the mesosalpinx: A case report. Int J Gynecol Pathol 22:209–212, 2003. - 5. Nisolle M, Donnez J: Peritoneal endometriosis, ovarian endometriosis, and adenomyotic nodules of the rectovaginal septum are three different entities. Fertil Steril 68:585–596, 1997. - 6. Sampson J: The development of the implantation theory for the origin of peritoneal endometriosis. Am J Obstet Gynecol 40:549–556, 1940. - 7. Soderberg CH, Dahlquist EH: Catamenial pneumothorax. Surgery 79:236–239, 1976. - 8. Tsunezuka Y, Oda M, Moriyama H, Ohshima M, Kurumaya H: Thoracoscopic findings and surgical management of catamenial hemopneumothorax. Ann Thorac Cardiovasc Surg 12:197–199, 2006.