{"paper_id":"5263166a-7bcc-4a33-ad06-8fa0454a22a1","body_text":"Abstract\nPurpose\nThe purpose of this study is to evaluate the “mushroom cap” sign on T2-weighted MR imaging in patients with submucosal tumors in the rectosigmoid colon.\nMethods\nFrom January 2001 to August 2009, 12 patients with four different diseases presenting or mimicking submucosal tumors in the rectosigmoid colon underwent colonic resection. All patients with deep endometriosis (n = 6), gastrointestinal stromal tumor (n = 4), metastasis from ovary cancer (n = 1), and carcinoid tumor (n = 1) had either an MRI of the rectum or pelvis before surgery. We evaluated the MRI findings and compared them with the macroscopic and microscopic observations in the resected specimens.\nResults\nIn all six cases of deep endometriosis, a characteristic “mushroom cap” shaped appearance was found on T2-weighted MR imaging. Heterogeneous low signal intensity of the hypertrophic muscularis propria, covered with high signal intensity of the mucosa and submucosa on T2-weighted MR images, looked like a “mushroom cap” with the pattern of intraluminal endophytic growth. In histological findings, deep endometriosis involved the submucosa (n = 4) or mucosa (n = 2). The “mushroom cap” sign was not present in any of the six other tumors.\nConclusion\nThe “mushroom cap” sign on T2-weighted MR imaging may be a characteristic sign for diagnosing deep rectosigmoid endometriosis.\nSimilar content being viewed by others\nReferences\nOlive DL, Schwartz LB (1993) Endometriosis. N Engl J Med 328:1759–1769\nMacafee CH, Greer HL (1960) Intestinal endometriosis. A report of 29 cases and a survey of the literature. J Obstet Gynaecol Br Emp 67:539–555\nKoga K, Osuga Y, Yano T, et al. (2003) Characteristic images of deeply infiltrating rectosigmoid endometriosis on transvaginal and transrectal ultrasonography. Hum Reprod 18:1328–1333\nChapron C, Jacob S, Dubuisson JB, et al. (2001) Laparoscopically assisted vaginal management of deep endometriosis infiltrating the rectovaginal septum. Acta Obstet Gynecol Scand 80:349–354\nChapron C, Dubuisson JB (2001) Management of deep endometriosis. Ann N Y Acad Sci 943:276–280\nMiller LS, Barbarevech C, Friedman LS (1994) Less frequent causes of lower gastrointestinal bleeding. Gastroenterol Clin North Am 23:21–52\nKelly P, McCluggage WG, Gardiner KR, Loughrey MB (2008) Intestinal endometriosis morphologically mimicking colonic adenocarcinoma. Histopathology 52:510–514\nCornillie FJ, Oosterlynck D, Lauweryns JM, Koninckx PR (1990) Deeply infiltrating pelvic endometriosis: histology and clinical significance. Fertil Steril 53:978–983\nKoninckx PR, Meuleman C, Demeyere S, Lesaffre E, Cornillie FJ (1991) Suggestive evidence that pelvic endometriosis is a progressive disease, whereas deeply infiltrating endometriosis is associated with pelvic pain. Fertil Steril 55:759–765\nHottat N, Larrousse C, Anaf V, et al. (2009) Endometriosis: contribution of 3.0-T pelvic MR imaging in preoperative assessment—initial results. Radiology 253:126–134\nMarcal L, Nothaft MA, Coelho F, Choi H (2010) Deep pelvic endometriosis: MR imaging. Abdom Imaging. doi:10.1007/s00261-010-9611-y\nGrasso RF, Di Giacomo V, Sedati P, Sizzi O, Florio G, Faiella E, Rossetti A, Del Vescovo R, Beomonte Zobel B (2009) Diagnosis of deep infiltrating endometriosis: accuracy of magnetic resonance imaging and transvaginal 3D ultrasonography. Abdom Imaging. doi:10.1007/s00261-009-9587-7\nYantiss RK, Clement PB, Young RH (2001) Endometriosis of the intestinal tract: a study of 44 cases of a disease that may cause diverse challenges in clinical and pathologic evaluation. Am J Surg Pathol 25:445–454\nBazot M, Darai E, Hourani R, et al. (2004) Deep pelvic endometriosis: MR imaging for diagnosis and prediction of extension of disease. Radiology 232:379–389\nAcknowledgement\nThis study was supported by the Samsung Biomedical Research Institute grant, #SBRI C-A7-425.\nAuthor information\nAuthors and Affiliations\nCorresponding author\nRights and permissions\nAbout this article\nCite this article\nYoon, J.H., Choi, D., Jang, KT. et al. Deep rectosigmoid endometriosis: “mushroom cap” sign on T2-weighted MR imaging. Abdom Imaging 35, 726–731 (2010). https://doi.org/10.1007/s00261-010-9643-3\nPublished:\nIssue date:\nDOI: https://doi.org/10.1007/s00261-010-9643-3","source_license":"CC0","license_restricted":false}