{"paper_id":"16b5d9d4-1915-4458-b2c6-d5b0d39213b1","body_text":"Abstract\nEndometriosis is a common disease, affecting approximately 10% of women of reproductive age. Several intersecting guidelines and consensus statements provide information on imaging diagnosis and surveillance strategies for endometriomas. SRU consensus panel recommendations provide information on initial detection of endometriosis on routine pelvic imaging. Revised American Society of Reproductive Medicine (rASRM) classification, the #ENZIAN classification, and the deep pelvic endometriosis index (dPEI) aim to assess the overall extent of disease and assist in presurgical planning. The Ovarian-Adnexal Reporting and Data System (O-RADS) aims to risk stratify lesions evaluated with US or MR based on their imaging morphology, from typical benign lesions to atypical presentations and malignant transformation. Emerging data shows increased risk of ovarian cancer in patients with endometriosis, especially following menopause and in those patients with long standing endometriosis. (Chen et al. in Front Oncol. 14:1329133, 2024;Streuli et al. in Climacteric. 20:138–143, 2017;Secosan et al. in Diagnostics (Basel). 10:134, 2020;Inceboz in Womens Health (Lond Engl). 11:711–715, 2015;Cassani et al. in Maturitas. 190, 2024;Gemmell et al. in Hum Reprod Update. 23:481–500, 2017;Giannella et al. in Cancers (Basel). 13:4026, 2021;) Current O-RADS guidelines mandate follow-up of endometriomas up to 2 years with further follow-up based on clinical factors. No consensus guidelines exist for imaging surveillance of patients with deep endometriosis from a malignancy standpoint. This review explores the imaging appearance of endometriomas, imaging features of malignant transformation, surveillance strategies and gaps in current literature, and attempts to better understand the risk of malignancy and to encourage further research for long-term imaging surveillance of endometriosis patients.\nSimilar content being viewed by others\nData availability\nNo datasets were generated or analysed during the current study.\nReferences\nChen B, Zhao L, Yang R, Xu T. New insights about endometriosis-associated ovarian cancer: pathogenesis, risk factors, prediction and diagnosis and treatment. Front Oncol. 2024;14: 1329133. https://doi.org/10.3389/fonc.2024.1329133\nStreuli I, Gaitzsch H, Wenger J-M, Petignat P. Endometriosis after menopause: physiopathology and management of an uncommon condition. Climacteric. 2017;20: 138–143. https://doi.org/10.1080/13697137.2017.1284781\nSecosan C, Balulescu L, Brasoveanu S, Balint O, Pirtea P, Dorin G, et al. Endometriosis in menopause-renewed attention on a controversial disease. Diagnostics (Basel). 2020;10: 134. https://doi.org/10.3390/diagnostics10030134\nInceboz U. Endometriosis after menopause. Womens Health (Lond Engl). 2015;11: 711–715. https://doi.org/10.2217/whe.15.59\nCassani C, Tedeschi S, Cucinella L, Morteo V, Camnasio CA, Tiranini L, et al. Menopause and endometriosis. Maturitas. 2024;190: 108129. https://doi.org/10.1016/j.maturitas.2024.108129\nGemmell LC, Webster KE, Kirtley S, Vincent K, Zondervan KT, Becker CM. The management of menopause in women with a history of endometriosis: a systematic review. Hum Reprod Update. 2017;23: 481–500. https://doi.org/10.1093/humupd/dmx011\nGiannella L, Marconi C, Di Giuseppe J, Delli Carpini G, Fichera M, Grelloni C, et al. Malignant transformation of postmenopausal endometriosis: A systematic review of the literature. Cancers (Basel). 2021;13: 4026. https://doi.org/10.3390/cancers13164026\nZondervan KT, Becker CM, Missmer SA. Endometriosis. N Engl J Med. 2020;382: 1244–1256. https://doi.org/10.1056/nejmra1810764\nYoung SW, Jha P, Chamié L, Rodgers S, Kho RM, Horrow MM, et al. Society of radiologists in ultrasound consensus on routine pelvic US for endometriosis. Radiology. 2024;311. https://doi.org/10.1148/radiol.232191\nMowers EL, Lim CS, Skinner B, Mahnert N, Kamdar N, Morgan DM, et al. Prevalence of endometriosis during abdominal or laparoscopic hysterectomy for chronic pelvic pain. Obstet Gynecol. 2016;127: 1045–1053. https://doi.org/10.1097/aog.0000000000001422\nSadłocha M, Toczek J, Major K, Staniczek J, Stojko R. Endometriosis: Molecular pathophysiology and recent treatment strategies—comprehensive literature review. Pharmaceuticals (Basel). 2024;17: 827. https://doi.org/10.3390/ph17070827\nTomassetti C, Johnson NP, Petrozza J, Abrao MS, Einarsson JI, Horne AW, et al. An international terminology for endometriosis, 2021. J Minim Invasive Gynecol. 2021;28: 1849–1859. https://doi.org/10.1016/j.jmig.2021.08.032\nThomassin-Naggara I, Lamrabet S, Crestani A, Bekhouche A, Wahab CA, Kermarrec E, et al. Magnetic resonance imaging classification of deep pelvic endometriosis: description and impact on surgical management. Hum Reprod. 2020;35: 1589–1600. https://doi.org/10.1093/humrep/deaa103\nAmerican Society for Reproductive Medicine. Revised American Society for Reproductive Medicine classification of endometriosis: 1996. Fertil Steril. 1997;67: 817–821. https://doi.org/10.1016/s0015-0282(97)81391-x\nKeckstein J, Saridogan E, Ulrich UA, Sillem M, Oppelt P, Schweppe KW, et al. The #Enzian classification: A comprehensive non‐invasive and surgical description system for endometriosis. Acta Obstet Gynecol Scand. 2021;100: 1165–1175. https://doi.org/10.1111/aogs.14099\nBarnard ME, Farland LV, Yan B, Wang J, Trabert B, Doherty JA, et al. Endometriosis typology and ovarian cancer risk. JAMA. 2024;332: 482–489. https://doi.org/10.1001/jama.2024.9210\nMelin A, Sparén P, Bergqvist A. The risk of cancer and the role of parity among women with endometriosis. Obstet Gynecol Surv. 2008;63: 156–157. https://doi.org/10.1097/01.ogx.0000305201.52162.49\nSadowski EA, Thomassin-Naggara I, Rockall A, Maturen KE, Forstner R, Jha P, et al. O-RADS MRI Risk Stratification System: Guide for Assessing Adnexal Lesions from the ACR O-RADS Committee. Radiology. 2022;303: 35–47. https://doi.org/10.1148/radiol.204371\nStrachowski LM, Jha P, Phillips CH, Blanchette Porter MM, Froyman W, Glanc P, et al. O-RADS US v2022: An update from the American college of radiology’s ovarian-adnexal reporting and data system US committee. Radiology. 2023;308. https://doi.org/10.1148/radiol.230685\nThomassin-Naggara I, Poncelet E, Jalaguier-Coudray A, Guerra A, Fournier LS, Stojanovic S, et al. Ovarian-Adnexal Reporting Data System Magnetic Resonance Imaging (O-RADS MRI) Score for Risk Stratification of Sonographically Indeterminate Adnexal Masses. JAMA Netw Open. 2020;3: e1919896. https://doi.org/10.1001/jamanetworkopen.2019.19896\nJha P, Gupta A, Baran TM, Maturen KE, Patel-Lippmann K, Zafar HM, et al. Diagnostic performance of the ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound risk score in women in the United States. JAMA Netw Open. 2022;5: e2216370. https://doi.org/10.1001/jamanetworkopen.2022.16370\nPatel-Lippmann KK, Gupta A, Martin MF, Phillips CH, Maturen KE, Jha P, et al. The roles of ovarian-adnexal reporting and data system US and ovarian-adnexal reporting and data system MRI in the evaluation of adnexal lesions. Radiology. 2024;312. https://doi.org/10.1148/radiol.233332\nTimmerman S, Valentin L, Ceusters J, Testa AC, Landolfo C, Sladkevicius P, et al. External validation of the ovarian-Adnexal Reporting and Data System (O-RADS) lexicon and the International Ovarian Tumor Analysis 2-step strategy to stratify ovarian tumors into O-RADS risk groups. JAMA Oncol. 2023;9: 225–233. https://doi.org/10.1001/jamaoncol.2022.5969\nFroyman W, Landolfo C, De Cock B, Wynants L, Sladkevicius P, Testa AC, et al. Risk of complications in patients with conservatively managed ovarian tumours (IOTA5): a 2-year interim analysis of a multicentre, prospective, cohort study. Lancet Oncol. 2019;20: 448–458. https://doi.org/10.1016/S1470-2045(18)30837-4\nLevine D, Brown DL, Andreotti RF, Benacerraf B, Benson CB, Brewster WR, et al. Management of asymptomatic ovarian and other adnexal cysts imaged at US Society of Radiologists in Ultrasound consensus conference statement. Ultrasound Q. 2010;26: 121–131. https://doi.org/10.1097/RUQ.0b013e3181f09099\nFroyman W, Wynants L, Landolfo C, Bourne T, Valentin L, Testa A, et al. Validation of the performance of International Ovarian Tumor Analysis (IOTA) methods in the diagnosis of early stage ovarian cancer in a non-screening population. Diagnostics (Basel). 2017;7: 32. https://doi.org/10.3390/diagnostics7020032\nPractice bulletin no. 174 summary: Evaluation and management of adnexal masses. Obstet Gynecol. 2016;128: 1193–1195. https://doi.org/10.1097/aog.0000000000001763\nSmith-Bindman R, Poder L, Johnson E, Miglioretti DL. Risk of malignant ovarian cancer based on ultrasonography findings in a large unselected population. JAMA Intern Med. 2019;179: 71–77. https://doi.org/10.1001/jamainternmed.2018.5113\nAndreotti RF, Timmerman D, Strachowski LM, Froyman W, Benacerraf BR, Bennett GL, et al. O-RADS US Risk Stratification and Management System: A Consensus Guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee. Radiology. 2020;294: 168–185. https://doi.org/10.1148/radiol.2019191150\nTesta AC, Timmerman D, Van Holsbeke C, Zannoni GF, Fransis S, Moerman P, et al. Ovarian cancer arising in endometrioid cysts: ultrasound findings. Ultrasound Obstet Gynecol. 2011;38: 99–106. https://doi.org/10.1002/uog.8970\nBrown DL, Doubilet PM, Miller FH, Frates MC, Laing FC, DiSalvo DN, et al. Benign and malignant ovarian masses: selection of the most discriminating gray-scale and Doppler sonographic features. Radiology. 1998;208: 103–110. https://doi.org/10.1148/radiology.208.1.9646799\nTimmerman D, Testa AC, Bourne T, Ameye L, Jurkovic D, Van Holsbeke C, et al. Simple ultrasound-based rules for the diagnosis of ovarian cancer. Ultrasound Obstet Gynecol. 2008;31: 681–690. https://doi.org/10.1002/uog.5365\nRobinson KA, Menias CO, Chen L, Schiappacasse G, Shaaban AM, Caserta MP, et al. Understanding malignant transformation of endometriosis: imaging features with pathologic correlation. Abdom Radiol (NY). 2020;45: 1762–1775. https://doi.org/10.1007/s00261-019-01914-7\nMatalliotakis M, Matalliotaki C, Trivli A, Zervou MI, Kalogiannidis I, Tzardi M, et al. Keeping an eye on perimenopausal and postmenopausal endometriosis. Diseases. 2019;7: 29. https://doi.org/10.3390/diseases7010029\nHuang K-J, Li Y-X, Wu C-J, Chang W-C, Wei L-H, Sheu B-C. Sonographic features differentiating early-stage ovarian clear cell carcinoma from endometrioma with atypical features. J Ovarian Res. 2022;15: 84. https://doi.org/10.1186/s13048-022-01019-8\nLa Vecchia C. Ovarian cancer: epidemiology and risk factors. Eur J Cancer Prev. 2017;26: 55–62. https://doi.org/10.1097/CEJ.0000000000000217\nReinhold C, Rockall A, Sadowski EA, Siegelman ES, Maturen KE, Vargas HA, et al. Ovarian-Adnexal Reporting Lexicon for MRI: A White Paper of the ACR Ovarian-Adnexal Reporting and Data Systems MRI Committee. J Am Coll Radiol. 2021;18: 713–729. https://doi.org/10.1016/j.jacr.2020.12.022\nCorwin MT, Gerscovich EO, Lamba R, Wilson M, McGahan JP. Differentiation of ovarian endometriomas from hemorrhagic cysts at MR imaging: utility of the T2 dark spot sign. Radiology. 2014;271: 126–132. https://doi.org/10.1148/radiol.13131394\nTogashi K, Nishimura K, Kimura I, Tsuda Y, Yamashita K, Shibata T, et al. Endometrial cysts: diagnosis with MR imaging. Radiology. 1991;180: 73–78. https://doi.org/10.1148/radiology.180.1.2052726\nKim HS, Kim TH, Chung HH, Song YS. Risk and prognosis of ovarian cancer in women with endometriosis: a meta-analysis. Br J Cancer. 2014;110: 1878–1890. https://doi.org/10.1038/bjc.2014.29\nWang C, Liang Z, Liu X, Zhang Q, Li S. The association between endometriosis, tubal ligation, hysterectomy and epithelial ovarian cancer: Meta-analyses. Int J Environ Res Public Health. 2016;13. https://doi.org/10.3390/ijerph13111138\nVigano E, Parazzini ’. P., Stoppelli F, Giambattista S, Vercellini E. Association between endometriosis and cancer: a comprehensive review and a critical analysis of clinical and epidemiological evidence. Gynecol Oncol. 2006;101: 331–341.\nKobayashi H, Sumimoto K, Moniwa N, Imai M, Takakura K, Kuromaki T, et al. Risk of developing ovarian cancer among women with ovarian endometrioma: a cohort study in Shizuoka, Japan. Int J Gynecol Cancer. 2007;17: 37–43. https://doi.org/10.1111/j.1525-1438.2006.00754.x\nMostoufizadeh M, Scully RE. Malignant tumors arising in endometriosis. Clin Obstet Gynecol. 1980;23: 951–963. https://doi.org/10.1097/00003081-198023030-00024\nStern RC, Dash R, Bentley RC, Snyder MJ, Haney AR, Robboy SJ. Malignancy in endometriosis: Frequency and comparison of ovarian and extraovarian types. Obstet Gynecol Surv. 2001;56: 415–416. https://doi.org/10.1097/00006254-200107000-00015\nGrandi G, Toss A, Cortesi L, Botticelli L, Volpe A, Cagnacci A. The association between endometriomas and ovarian cancer: Preventive effect of inhibiting ovulation and menstruation during reproductive life. Biomed Res Int. 2015;2015: 751571. https://doi.org/10.1155/2015/751571\nGuo S-W. Cancer-associated mutations in endometriosis: shedding light on the pathogenesis and pathophysiology. Hum Reprod Update. 2020;26: 423–449. https://doi.org/10.1093/humupd/dmz047\nKrawczyk N, Banys-Paluchowski M, Schmidt D, Ulrich U, Fehm T. Endometriosis-associated malignancy. Geburtshilfe Frauenheilkd. 2016;76: 176–181. https://doi.org/10.1055/s-0035-1558239\nKobayashi H, Kajiwara H, Kanayama S, Yamada Y, Furukawa N, Noguchi T, et al. Molecular pathogenesis of endometriosis-associated clear cell carcinoma of the ovary (review). Oncol Rep. 2009;22: 233–240. https://doi.org/10.3892/or_00000429\nYamaguchi K, Mandai M, Toyokuni S, Hamanishi J, Higuchi T, Takakura K. Contents endometriotic cysts, especially high concentration free iron, possible cause carcinogenesis cysts through iron-induced persistent oxidative stress. Clin Cancer Res. 2008;14: 32–40. https://doi.org/10.1158/1078-0432.CCR07-1614\nMunksgaard PS, Blaakaer J. The association between endometriosis and ovarian cancer: a review of histological, genetic and molecular alterations. Gynecol Oncol. 2012;124: 164–169. https://doi.org/10.1016/j.ygyno.2011.10.001\nDePriest PD, Banks ER, Powell DE, van Nagell JR Jr, Gallion HH, Puls LE, et al. Endometrioid carcinoma of the ovary and endometriosis: the association in postmenopausal women. Gynecol Oncol. 1992;47: 71–75. https://doi.org/10.1016/0090-8258(92)90079-x\nMcDermott S, Oei TN, Iyer VR, Lee SI. MR imaging of malignancies arising in endometriomas and extraovarian endometriosis. Radiographics. 2012;32: 845–863. https://doi.org/10.1148/rg.323115736\nZhang X, Li M, Tang Z, Li X, Song T. Differentiation between endometriosis-associated ovarian cancers and non- endometriosis-associated ovarian cancers based on magnetic resonance imaging. Br J Radiol. 2021;94: 20201441. https://doi.org/10.1259/bjr.20201441\nKumar S, Munkarah A, Arabi H, Bandyopadhyay S, Semaan A, Hayek K, et al. Prognostic analysis of ovarian cancer associated with endometriosis. Am J Obstet Gynecol. 2011;204: 63.e1–7. https://doi.org/10.1016/j.ajog.2010.08.017\nTakeuchi M, Matsuzaki K, Uehara H, Nishitani H. Malignant transformation of pelvic endometriosis: MR imaging findings and pathologic correlation. Radiographics. 2006;26: 407–417. https://doi.org/10.1148/rg.262055041\nTanaka YO, Okada S, Yagi T, Satoh T, Oki A, Tsunoda H, et al. MRI of endometriotic cysts in association with ovarian carcinoma. AJR Am J Roentgenol. 2010;194: 355–361. https://doi.org/10.2214/AJR.09.2985\nDhanda S, Thakur M, Kerkar R, Jagmohan P. Diffusion weighted imaging gynecologic tumors: diagnostic pearls potential pitfalls. Radiographics. 2014;34: 1393–1416.\nCheung E, Gillks CB. Tumors ovary. : WHO classification female genital Tumors. Lyon, France; 2020. pp. 31–167.\nHauptmann S, Friedrich K, Redline R, Avril S. Ovarian borderline tumors in the 2014 WHO classification: evolving concepts and diagnostic criteria. Virchows Arch. 2017;470: 125–142. https://doi.org/10.1007/s00428-016-2040-8\nTsuboyama T, Sato K, Ota T, Fukui H, Onishi H, Nakamoto A, et al. MRI of borderline epithelial ovarian tumors: Pathologic correlation and diagnostic challenges. Radiographics. 2022;42: 2095–2111. https://doi.org/10.1148/rg.220068\nHan JW, Kim KA, Chang HY, Kim JW, Park YS, Lee J, et al. Newly categorized seromucinous tumor of the ovary: Magnetic resonance imaging findings. J Comput Assist Tomogr. 2019;43: 119–127. https://doi.org/10.1097/RCT.0000000000000776\nZhao SH, Qiang JW, Zhang GF, Ma FH, Cai SQ, Li HM, et al. Diffusion-weighted MR imaging for differentiating borderline from malignant epithelial tumours of the ovary: pathological correlation. Eur Radiol. 2014;24: 2292–2299. https://doi.org/10.1007/s00330-014-3236-4\nJia S-Z, Zhang J-J, Yang J-J, Xiang Y, Liang Z, Leng J-H. Risk of synchronous endometrial disorders in women with endometrioid borderline tumors of the ovary. J Ovarian Res. 2018;11. https://doi.org/10.1186/s13048-018-0405-0\nTakeuchi M, Matsuzaki K, Harada M. Ovarian adenofibromas and cystadenofibromas: magnetic resonance imaging findings including diffusion-weighted imaging. Acta Radiol. 2013;54: 231–236. https://doi.org/10.1258/ar.2012.120516\nThomassin-Naggara I, Aubert E, Rockall A, Jalaguier-Coudray A, Rouzier R, Daraï E, et al. Adnexal masses: development and preliminary validation of an MR imaging scoring system. Radiology. 2013;267: 432–443. https://doi.org/10.1148/radiol.13121161\nChamié LP, VanBuren WM, Xiao L, Pires Franco IV, Feldman MK, Causa Andrieu P, et al. Postmenopausal endometriosis: Clinical insights and imaging considerations. Radiographics. 2024;44: e240046. https://doi.org/10.1148/rg.240046\nAuthor information\nAuthors and Affiliations\nContributions\nEach author contributed one section of the manuscript. Authors Patel-Lippmann, Phillips, Jha, Burk, and Suarez-Weiss contributed to the figures. All authors reviewed the manuscript.\nCorresponding authors\nEthics declarations\nCompeting interests\nPriyanka Jha: O-RADS Steering Committee Member and Honorarium from World Class CME Angela Tong: Speaker honorarium from Siemens Healthineers × 1; Research support from Siemens Healthineer in the form of software and hardware.\nAdditional information\nPublisher's Note\nSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.\nRights and permissions\nSpringer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.\nAbout this article\nCite this article\nSuarez-Weiss, K.E., Patel-Lippmann, K., Phillips, C. et al. Endometriosis: assessment on O-RADS and risk of malignant transformation. Abdom Radiol 50, 4865–4877 (2025). https://doi.org/10.1007/s00261-025-04885-0\nReceived:\nRevised:\nAccepted:\nPublished:\nVersion of record:\nIssue date:\nDOI: https://doi.org/10.1007/s00261-025-04885-0","source_license":"CC0","license_restricted":false}