{"paper_id":"6255b7e7-76b6-45a4-a468-21a67e5ac9bd","body_text":"letter to the editor\nkorean j intern med 2012;27:353-355\nhttp://dx.doi.org/10.3904/kjim.2012.27.3.353 \npISSN 1226-3303    eISSN 2005-6648\nhttp://www.kjim.or.kr\nisolated Bowel \nendometriosis \nr esembling a Myogenic \ntumor on endoscopic \nUltrasonography\nTo the Editor,\nBowel endometriosis is defined as the presence of en -\ndometrial glands and stroma infiltrating the bowel wall \nreaching at least the subserous fat or adjacent to the \nneurovascular branches (subserous plexus) [1]. In gen -\neral, colonoscopy offers little assistance in the diagnosis \nof bowel endometriosis because the lesions are typically \nsubmucosal and usually not visible during this exami -\nnation [2].\nA 48-year-old woman was referred to our hospital for \nfurther evaluation of an incidental submucosal tumor \ndetected during colonoscopy for a health checkup. Re -\ncently, she had been suffering from cyclic, intractable \npelvic pain, which was not associated with altered bow -\nel habit or rectal bleeding. The physical examination \nrevealed no specific findings, such as abdominal tender -\nness or palpable masses in the abdomen.\nThe laboratory examination showed an elevated can-\ncer antigen (CA) 125 level at 110 IU/mL, while other \nvalues were within the normal limits. The gynecologic \nexamination revealed a normal vagina, uterus, and uter -\nine cervix. Transvaginal ultrasonography revealed mul -\ntiple myomas in the uterine wall, but no abnormalities \nin either ovary. Abdominopelvic computed tomography \nshowed no specific findings. Colonoscopy showed sub -\nepithelial compression with a smooth mucosal surface \nin the sigmoid colon 25 cm from the anal verge (Fig. 1). \nAn endoscopic ultrasonography (EUS) miniprobe (UM-\n2R, Olympus Japan, Tokyo, Japan) was used to evaluate \nthe subepithelial mass at a frequency of 12 MHz. This \ndemonstrated a homogenous, hypoechoic, indistinctly \nshaped lesion located in the fourth layer (muscularis \npropria) (Fig. 2). Based on the EUS miniprobe findings, \nthe possibility of a myogenic tumor, such as a leiomyo -\nma or gastrointestinal stromal tumor, was considered \nin the differential diagnosis, but the presence of bowel \nendometriosis, although though to be less probable, \ncould not be excluded with certainty. Bowel endometri -\nosis had to be ruled out because the patient had cyclic, \nintractable pelvic pain; the CA-125 level was elevated at \n110 IU/mL; and the location was the sigmoid colon. The \npatient underwent laparoscopy-assisted sigmoidectomy \nto confirm the diagnosis. Normal-appearing peritone -\num was found at laparoscopy. The gross examination of \nthe resected sigmoid colon revealed a 1.3-cm ill-defined \nhard mass in the wall, indenting the overlying serosal \nsurface (Fig. 3A). No remarkable findings were noted \nCopyright © 2012 The Korean Association of Internal Medicine\nThis is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-\ncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. \nReceived : d ecember 10, 2011\nRevised   : december 21, 2011\nAccepted : j anuary 5, 2012\nCorrespondence to Joon Seong Lee, M.D. \nInstitute for d igestive Research, Soonchunhyang University Hospital, 59 d aesagwan-ro, Yongsan-gu, Seoul 140-743, Korea\nTel: 82-2-709-9691, Fax: 82-2-709-9696, E-mail: drjslee@dreamwiz.com\nFigure 1. Colonoscopy revealed subepithelial compression with \nnormal overlying mucosa.\n\n\n354    The Korean j ournal of Internal Medicine Vol. 27, No. 3, September 2012\nhttp://dx.doi.org/10.3904/kjim.2012.27.3.353 http://www.kjim.or.kr\nin the mucosal surface. The mass consisted of an ir -\nregularly thickened proper muscle layer. Histologically, \nthe mass consisted of irregularly arranged, proli ferated \nsmooth muscle cells of the proper muscle layer with \nembedded endometrial glands and stromal cells, con -\nsistent with bowel endometriosis (Fig. 3B).\nOn EUS, bowel endometriosis consists of heteroge -\nneous or hypoechoic crescent-shaped lesions, involv -\ning the serosal, muscularis propria, and occasionally \nsubmucosal layers and sparing the mucosal layers [3-5]. \nBowel endometriosis shows thickening of the muscu -\nlaris propria and fibrotic adhesions and convergence of \nthe serosa. This appears to be responsible for the typical \nEUS pattern. The heterogeneous echo finding is caused \nby the presence of the so-called chocolate cysts that \nresult from hemorrhage within the implants induced \nby the hormonal cycle [4]. Bowel endometriosis often \nextends outside the rectal wall into the rectovaginal \nseptum or into the posterior lower uterine wall; this \ninfiltrative quality of the implants can be mistaken for a \nmalignant process [4]. EUS is even less accurate for en -\ndometriotic nodules located away from the EUS probe, \nsuch as endometriosis in the uterosacral ligaments \nand ovaries. The accuracy for detection of nodules in \nthe uterosacral ligaments or ovaries is 56% and 53%, \nrespectively [3]. In our case, the normal-appearing \nperitoneum on laparoscopy was thought to explain the \nisolated bowel endometriosis, rather than missing peri -\nrectosigmoid endometriosis. In summary, this case re -\nport demonstrates that bowel endometriosis should be \nadded to the shortlist of diseases that cause hypoechoic \nlesions located on the muscularis layer on EUS exami -\nnation, of which the characteristic lesion is a myogenic \ntumor.\nKeywords: Endometriosis; Endosonography\nConflict of interest\nNo potential conflict of interest relevant to this article \nis reported.\nFigure 3. Pathology findings. (A) Macroscopically, the cut section of sigmoid colon showed an irregularly thickened proper muscle \nlayer and an indented serosal surface with retracted pericolic soft tissue. (B) Microscopically, endometrial glands and stromal cells were \nembedded in the thickened proper muscle layer (H&E, × 40; inset, × 200).\nA B\nFigure 2.  Endoscopic ultrasonography using a miniprobe \nshowed an indistinctly shaped hypoechoic lesion arising from \nthe muscularis propria layer.\n\n\nl ee TH, et al. Isolated bowed endometriosis    355\nhttp://dx.doi.org/10.3904/kjim.2012.27.3.353 http://www.kjim.or.kr\nTae Hee Lee1, Joon Seong Lee1, Dong Wha Lee2, \nand Jin-Oh Kim1\n1Institute for Digestive Research and 2Department of \nPathology, Soonchunhyang University Hospital, Seoul, \nKorea\nREFERENCES\n1. Remorgida V, Ferrero S, Fulcheri E, Ragni N, Martin DC. \nBowel endometriosis: presentation, diagnosis, and treat -\nment. Obstet Gynecol Surv 2007;62:461-470.\n2. Redwine DB, Sharpe DR. Laparoscopic surgery for intestinal \nand urinary endometriosis. Baillieres Clin Obstet Gynaecol \n1995;9:775-794.\n3. Delpy R, Barthet M, Gasmi M, et al. Value of endorectal \nultrasonography for diagnosing rectovaginal septal endome -\ntriosis infiltrating the rectum. Endoscopy 2005;37:357-361.\n4. Pishvaian AC, Ahlawat SK, Garvin D, Haddad NG. Role \nof EUS and EUS-guided FNA in the diagnosis of symp -\ntomatic rectosigmoid endometriosis. Gastrointest Endosc \n2006;63:331-335.\n5. Chung SK, Lee SH, Son BS, et al. Rectal endometriosis that is \ndifficult to differentiate from endoscopically resectable sub -\nepitherial lesion. Korean J Gastrointest Endosc 2010;41:319-\n323.","source_license":"CC0","license_restricted":false}