A Rare Case of Malignant Transformation: Squamous Cell Carcinoma Arising on the Basis of an Ovarian Mature Cystic Teratoma

A Rare Case of Malignant Transformation: Squamous Cell Carcinoma Arising on the Basis of an Ovarian Mature Cystic Teratoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Rare Case of Malignant Transformation: Squamous Cell Carcinoma Arising on the Basis of an Ovarian Mature Cystic Teratoma Furkan ÖZDEM, Sümeyya Duran KAYMAK, Berna TURHAN, Candost HANEDAN, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5661121/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 May, 2025 Read the published version in BMC Women's Health → Version 1 posted 10 You are reading this latest preprint version Abstract Background Ovarian mature cystic teratomas (MCTs) are the most prevalent benign ovarian tumors, with rare potential for malignant transformation, most commonly into squamous cell carcinoma. Accurate diagnosis is crucial for optimal management and prognosis. Case Presentation: A 27-year-old woman presented with a year-long history of intermittent abdominal and groin pain. Imaging studies, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), revealed a mixed solid-cystic lesion in the left adnexal region, consistent with an MCT exhibiting radiologic signs of malignancy. The patient underwent unilateral salpingo-oophorectomy, and intraoperative frozen section analysis suggested a mature cystic teratoma. However, definitive histopathological examination confirmed squamous cell carcinoma arising from the MCT. This case highlights the limitations of frozen section analysis in detecting malignancy. Conclusion Malignant transformation of MCTs, though rare, poses significant diagnostic and therapeutic challenges. Comprehensive preoperative imaging and meticulous postoperative histopathological evaluation are essential for accurate diagnosis and effective management. This case underscores the importance of interdisciplinary collaboration in addressing complex gynecologic pathologies. Ovarian Mature Cystic Teratoma Squamous Cell Carcinoma Malignant Conversion Ovarian Tumours Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Ovarian mature cystic teratomas (MCTs), colloquially known as ovarian dermoid cysts, are the most frequent benign ovarian tumours occurring in women in their second and third decades. MCTs constitute approximately 20% of benign ovarian neoplasms diagnosed during the postmenopausal period ( 1 ). They represent 95% of all teratomas, approximately 70% of all germ cell tumours, and 10% of neoplasms originating from the ovaries ( 2 ). Synchronous bilateral ovarian involvement is documented in about 10–15% of cases ( 3 ). MCTs generally remain asymptomatic until they attain substantial size. The most common clinical manifestations are abdominal and groin pain, which result from the mass effect on adjacent tissues and organs. Potential complications include ovarian torsion, rupture, peritonitis, or infection ( 4 ). Although rare, malignant transformations such as squamous cell carcinoma can emerge from the foundation of mature cystic teratomas (MCTs), often indicating a poor prognosis ( 1 ). Early diagnosis of such malignant transformations is crucial to pre-empt complications like invasion and metastasis, utilizing diagnostic modalities including ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) ( 4 , 6 ). This study details a case involving squamous cell carcinoma that developed on the rare substrate of an ovarian mature cystic teratoma. Case Report A 27-year-old woman presented to our clinic reporting intermittent abdominal and groin pain persisting for a year. Patient had no known additional medical conditions and was not on any medication. Surgical history included a caesarean section. Laboratory evaluations revealed a mildly increased white blood cell count of 10,650 cells/mL. Hematocrit level and other biochemical parameters were within normal limits. Notably, tumor markers were elevated: carcinoembryonic antigen (CEA) at 7.04 µg/L, cancer antigen 19 − 9 (CA19-9) at 82.6 U/mL, and cancer antigen 125 (CA125) at 106 U/mL. A contrast-enhanced abdominopelvic CT examination conducted on the patient showed a predominantly mixed solid-cystic lesion, approximately 13x11x9 cm in size, arising from the left adnexal loge and extending to the midline at the umbilical level. The lesion displayed fat-fluid levels and calcifications. Its anterosuperior part contained a solid component about 5.5 cm thick at its widest, with lobulated margins and a heterogeneous internal texture. This component blurred the interface with adjacent intestinal attachments and extended into the surrounding peritoneal fat (Figs. 1 and 2 ). The patient underwent pelvic magnetic resonance imaging (MRI) to evaluate possible invasion into neighbouring tissues and organs. The MRI revealed a solid component with heterogeneous contrast enhancement and diffusion restriction, alongside areas demonstrating signal loss compatible with fat content and fat-fluid levels in T2 fat-suppressed sequences (Fig. 3 ). The lesion showed no clear evidence of invasive behaviour. Given the CT and MRI results, which were radiologically indicative of a mature cystic teratoma with malignant transformation, surgical intervention was scheduled. Ovarian mass removed by unilateral salpingoophrectomy (Fig. 4 ). The ovarian mass evaluated by an experienced gynecopathologist during the operation, was reported as a mature cystic teratoma. The final histopathological examination revealed squamous cell carcinoma derived from the mature cystic teratoma. This unexpected outcome underscores the limitations of frozen section analysis in certain cases and the necessity for comprehensive tissue examination. Discussion Ovarian germ cell tumours (GCTs) are uncommon malignancies that derive from ovarian germ cells ( 4 ). Among these, teratomas represent the most frequent germ cell tumour type, predominantly seen in younger women. Teratomas are classified into three histological variants: mature, immature, and monodermal teratomas (struma ovarii). The MCT subtype is the most common, accounting for 95% of teratomas and 10% of all ovarian germ cell tumours ( 3 , 4 ). MCTs are distinctly bounded, encapsulated cystic tumours that encompass components from at least two germinal layers—ectoderm, mesoderm, and endoderm—featuring diverse tissue and organ components like hair, skin, neural structures, fat, sebaceous glands, and teeth ( 4 ). MCTs rarely demonstrate malignant transformation, with an incidence rate ranging from 1.5-2% ( 5 , 6 ). The predominant malignancy arising from such transformations is squamous cell carcinoma, comprising 80% of these cases, with other variations including adenocarcinoma, small cell carcinoma, malignant melanoma, and sarcoma ( 5 , 6 ). Studies have shown that these transformations typically occur in postmenopausal women, and the mean age at diagnosis is reported to be 53.5 years ( 6 ). The most frequent manifestations in squamous cell carcinoma cases originating from MCTs are abdominal pain (47.3%) and the presence of an abdominal mass (26.0%) ( 7 ). In suspicious cases, preoperative radiologic evaluation plays a crucial role in anticipating malignant transformation and guiding surgical decision-making. Şahin et al. emphasized that tumor markers are not always correlated with tumor size ( 9 ). This suggests that malignancy risk is not solely size-dependent but also related to specific imaging features. In our case, radiological findings were key to raising suspicion for malignant transformation and directing the surgical approach. These tumours may exhibit a complex architecture featuring both cystic and solid components, reflecting their diverse tissue and organ content. This variability appearance can sometimes pose diagnostic challenges. In line with this, Pelayo et al. emphasized that although most mature cystic teratomas and serous cystadenomas are correctly classified by ultrasound, certain features—especially the presence of solid components or acoustic shadows—may lead to misclassification, underlining the importance of expert interpretation in radiological evaluation ( 10 ). Typically identified as fatty, hyperechoic lesions during routine ultrasound (US) screenings, MCTs may show characteristic but not definitive signs such as the dot-dash sign, indicative of internal hair, and the tip of the iceberg sign, related to posterior acoustic attenuation. Often, their similar appearance to complex haemorrhagic cysts necessitates further evaluation using cross-sectional imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) ( 4 ). These imaging techniques effectively visualize characteristics like fat-fluid levels, calcifications, and structural thickening. In cases like ours, CT findings of well-defined tumour margins, sizes over 10 cm, and cauliflower-like appearances might prompt concerns for malignant transformation. Moreover, MRI can accurately delineate the extent of a tumour’s malignant component, invasion, and metastasis with high sensitivity ( 4 ). The primary treatment for MCTs with malignant changes is surgical intervention. Research has demonstrated that combining total hysterectomy and bilateral salpingo-oophorectomy with neoadjuvant chemotherapy markedly enhances survival. Moreover, the study highlighted that lymphadenectomy and omentectomy lack verified effectiveness in decreasing mortality. Additionally, the research reported no observable difference in outcomes between fertility-preserving and radical surgical approaches, and there was no established efficacy for postoperative radiotherapy in enhancing treatment results ( 8 ). Conclusion Ovarian mature cystic teratomas are frequently occurring benign tumours that mainly impact young women. On occasion, these teratomas can malignantly transform, most commonly into squamous cell carcinoma, thereby elevating the risks of morbidity and mortality. Consequently, prompt diagnosis, diligent follow-up after treatment, and a comprehensive, interdisciplinary approach are essential in the management of these complications. Declarations Acknowledgements: Not applicable. Author Contributions : Furkan Özdem was responsible for the conception and design of the study, conducted the literature review, wrote the manuscript, and performed the critical review. Sümeyya Duran Kaymak contributed to the conception of the study, supervised the work, and participated in manuscript writing. Berna Turhan also contributed to the conception of the study, supervision, and manuscript writing. Similarly, Candost Hanedan played a role in the conception of the study, supervision, and manuscript writing. Sezgi Barlas and Özge Demirsoy contributed to the conception of the study and provided supervision. Rasime Pelin Kavak also contributed to the conception of the study and supervision. Funding: The authors declared that this study has received no financial support or funding. Data Availability : All data contained in this study can be obtained from the corresponding author under reasonable request. Compliance with Ethical Standards Conflict of interest Furkan Özdem, Sümeyya Duran Kaymak, Berna Turhan, Candost Hanedan, Sezgi Barlas, Özge Demirsoy and Rasime Pelin Kavak have read and approved the manuscript, and, subject to acceptance, authors will transfer copyright to the Publisher; there is no ethical problem or conflict of interest, and there has been no duplicate publication or submission elsewhere. Ethical Approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Consent for Publication: The written informed consent was obtained from subjects and/or their legal guardians for publication References St Louis, M., Mangal, R., Stead, T. S., Sosa, M., & Ganti, L. (2022). Ovarian Dermoid Tumor. Cureus, 14(7), e27233. https://doi.org/10.7759/cureus.27233 Cong, L., Wang, S., Yeung, S. Y., Lee, J. H. S., Chung, J. P. W., & Chan, D. Y. L. (2023). Mature cystic teratoma: an integrated review. International Journal of Molecular Sciences, 24(7), 6141. Deeksha, H. S., Pajai, S., Patel, D. J., Navalihiremath, V. U., & Jyotsna, G. (2024). Unraveling the Enigma: A Case Report on Unilateral Ovarian Dermoid Cyst. Cureus, 16(2). Sahin, H., Abdullazade, S., & Sanci, M. (2017). Mature cystic teratoma of the ovary: a cutting edge overview on imaging features. Insights into imaging, 8, 227-241. Matalliotakis, M., Matalliotaki, C., Tsakiridis, I., Dagklis, T., Michos, G., Romanos, A., Krithinakis, K., & Kalogiannidis, I. A. (2024). Co-existence of Ovarian Teratomas With Other Gynecological Tumors. Cureus, 16(4), e58068. https://doi.org/10.7759/cureus.58068 Montebello, A., Maniscalco, N., Grech, M., Cuschieri, A., & Brockdorff, K. M. V. (2024). Squamous cell carcinoma of the ovary arising from a mature cystic teratoma associated with hypercalcaemia. British Journal of Hospital Medicine, 1-5. Peluso, E., Edwards, W. F., & Janco, J. M. T. (2024). Metastatic squamous cell carcinoma arising from mature teratoma of the ovary: Description of multi-modality treatment including incorporation of adjuvant immunotherapy and maintenance PARP inhibitor therapy. Gynecologic Oncology Reports, 52, 101371. Li, C., Zhang, Q., Zhang, S., Dong, R., Sun, C., Qiu, C., ... & Kong, B. (2019). Squamous cell carcinoma transformation in mature cystic teratoma of the ovary: a systematic review. BMC cancer, 19, 1-12. Sahin, F., Aktürk, E., Günkaya, O. S., Özdemir, S., Konal, M., Genç, S., ... & Akbayir, O. (2023). Borderline ovarian tumors: twenty years of experience at a tertiary center. Anatolian Current Medical Journal , 5 (3), 196-200. Pelayo, M., Sancho-Sauco, J., Sánchez-Zurdo, J., Perez-Mies, B., Abarca-Martínez, L., Cancelo-Hidalgo, M. J., ... & Pelayo-Delgado, I. (2023). Application of Ultrasound scores (subjective Assessment, simple rules Risk Assessment, ADNEX Model, O-RADS) to Adnexal masses of difficult classification. Diagnostics , 13 (17), 2785. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 02 May, 2025 Read the published version in BMC Women's Health → Version 1 posted Editorial decision: Accepted 24 Apr, 2025 Reviews received at journal 22 Apr, 2025 Reviews received at journal 13 Apr, 2025 Reviewers agreed at journal 13 Apr, 2025 Reviewers agreed at journal 13 Apr, 2025 Reviews received at journal 11 Apr, 2025 Reviewers agreed at journal 11 Apr, 2025 Reviewers invited by journal 11 Apr, 2025 Submission checks completed at journal 10 Apr, 2025 First submitted to journal 09 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5661121","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":442333533,"identity":"880bf4e4-4a39-48fd-83bc-83fcef6cc916","order_by":0,"name":"Furkan ÖZDEM","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+0lEQVRIiWNgGAWjYBAC9gYGZiiT+fjHDxUgmrkBrxaeA3AtbGnMEmdAWhiJ1sKjxsDbBmIQ0iKR+9jg5w6bfH7pHrYHkvNqo/nbgVp+VGzDoyXdOLH3TJrlzDlnjxsUbjueO+MwYwNjz5nbOLXYS6QxH+BtO2xgcCMvQUJy27HcBqAWZsY23Fp4gFoO/m37b2B/I8dAgnfOsdz5xGhJ5m07YGAgkWMmwdtQk7uBoBaeZ8zGsm3JBhI30pKNJY4dyN0I1HIQn1942NOYJd+22Rnwz0g++PBDTV3uvPOHDz74UYFbCzo4DCYPEK0eCOpIUTwKRsEoGAUjBAAAzbNYBGQtOX8AAAAASUVORK5CYII=","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":true,"prefix":"","firstName":"Furkan","middleName":"","lastName":"ÖZDEM","suffix":""},{"id":442333535,"identity":"6d6e88ab-a1b6-4a04-8759-42e4b9477673","order_by":1,"name":"Sümeyya Duran KAYMAK","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sümeyya","middleName":"Duran","lastName":"KAYMAK","suffix":""},{"id":442333536,"identity":"11a08796-118f-47d3-8a48-55ea34eb9479","order_by":2,"name":"Berna TURHAN","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Berna","middleName":"","lastName":"TURHAN","suffix":""},{"id":442333537,"identity":"6f2eeb86-ac70-4546-8dc6-bf08c98acd6c","order_by":3,"name":"Candost HANEDAN","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Candost","middleName":"","lastName":"HANEDAN","suffix":""},{"id":442333538,"identity":"298a912a-5bbb-4394-bcfe-d19437378b00","order_by":4,"name":"Sezgi BARLAS","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sezgi","middleName":"","lastName":"BARLAS","suffix":""},{"id":442333539,"identity":"6583a01b-c0b9-4aa3-8ba8-125ece009864","order_by":5,"name":"Özge DEMİRSOY","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Özge","middleName":"","lastName":"DEMİRSOY","suffix":""},{"id":442333540,"identity":"c60dfa65-ea9b-45d5-ab1b-55312403b3a5","order_by":6,"name":"Rasime Pelin KAVAK","email":"","orcid":"","institution":"Health Sciences University Ankara Etlik City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Rasime","middleName":"Pelin","lastName":"KAVAK","suffix":""}],"badges":[],"createdAt":"2024-12-17 11:08:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5661121/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5661121/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12905-025-03755-7","type":"published","date":"2025-05-02T15:57:37+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":80587512,"identity":"7551da98-3b61-49f9-85fc-5e7e317ae3f0","added_by":"auto","created_at":"2025-04-15 01:21:43","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":732064,"visible":true,"origin":"","legend":"\u003cp\u003eThe axial slice of the contrast-enhanced abdominopelvic CT (0.625 mm slice thickness) scan illustrates a significant lesion emanating from the left adnexal region extending to the abdominal midline. The lesion features an oval-shaped component characteristic of a mature cystic teratoma, evident by its fat-fluid levels (highlighted by the white arrow). Directly anterior to this, there is a lobulated and heterogeneous solid component (indicated by the white star), which is suggestive of malignant transformation.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5661121/v1/518f3cd8f0ea955873c9ca1c.png"},{"id":80587515,"identity":"9ce270cd-6738-4d31-aa90-20f8ac9273f5","added_by":"auto","created_at":"2025-04-15 01:21:43","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":883048,"visible":true,"origin":"","legend":"\u003cp\u003eThe coronal plane of the contrast-enhanced abdominopelvic CT (0.625 mm slice thickness) scan reveals a complex lesion located in the abdominal cavity. An oval-shaped, fat-rich mature cystic teratoma is identifiable, marked with a white triangle. Notably, the teratoma contains calcifications, highlighted by a white arrow. Positioned superiorly, a component suggestive of malignant transformation is visible, indicated by a white star.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5661121/v1/2d1d576114693dc07f8245b3.png"},{"id":80588158,"identity":"39038043-49f7-4519-8484-e9113f63c694","added_by":"auto","created_at":"2025-04-15 01:37:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1074478,"visible":true,"origin":"","legend":"\u003cp\u003eT2-weighted fat-suppressed MRI image in the axial plane showcases a clearly defined, oval-shaped lesion consistent with a mature cystic teratoma, evident by the fat-fluid levels marked with a white arrow. Adjacent to this, on the right anterolateral aspect, lies a heterogeneous, hyperintense soft tissue component, indicated by a white star, suggestive of malignant transformation.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5661121/v1/c82d82353805b40d459d679a.png"},{"id":80587523,"identity":"5067f4cc-724d-464c-896a-ab05a867cedf","added_by":"auto","created_at":"2025-04-15 01:21:43","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2244469,"visible":true,"origin":"","legend":"\u003cp\u003ePostoperative imaging of the lesion. The lesion features an oval-shaped component characteristic of a mature cystic teratoma (highlighted by the white arrow in figure b). Directly anterior to this, there is a lobulated and heterogeneous solid component (indicated by the white star in figure b), which is suggestive of malignant transformation.\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-5661121/v1/67065096c533fe8c7b91bfd8.png"},{"id":81988111,"identity":"8b8d4321-e550-4ffd-9bd6-d73c347d5233","added_by":"auto","created_at":"2025-05-05 16:07:59","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6996349,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5661121/v1/3b719d38-22ec-425c-bdc5-6b2ac21290ea.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Rare Case of Malignant Transformation: Squamous Cell Carcinoma Arising on the Basis of an Ovarian Mature Cystic Teratoma","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOvarian mature cystic teratomas (MCTs), colloquially known as ovarian dermoid cysts, are the most frequent benign ovarian tumours occurring in women in their second and third decades. MCTs constitute approximately 20% of benign ovarian neoplasms diagnosed during the postmenopausal period (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). They represent 95% of all teratomas, approximately 70% of all germ cell tumours, and 10% of neoplasms originating from the ovaries (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Synchronous bilateral ovarian involvement is documented in about 10\u0026ndash;15% of cases (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMCTs generally remain asymptomatic until they attain substantial size. The most common clinical manifestations are abdominal and groin pain, which result from the mass effect on adjacent tissues and organs. Potential complications include ovarian torsion, rupture, peritonitis, or infection (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlthough rare, malignant transformations such as squamous cell carcinoma can emerge from the foundation of mature cystic teratomas (MCTs), often indicating a poor prognosis (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Early diagnosis of such malignant transformations is crucial to pre-empt complications like invasion and metastasis, utilizing diagnostic modalities including ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis study details a case involving squamous cell carcinoma that developed on the rare substrate of an ovarian mature cystic teratoma.\u003c/p\u003e"},{"header":"Case Report","content":"\u003cp\u003eA 27-year-old woman presented to our clinic reporting intermittent abdominal and groin pain persisting for a year. Patient had no known additional medical conditions and was not on any medication. Surgical history included a caesarean section. Laboratory evaluations revealed a mildly increased white blood cell count of 10,650 cells/mL. Hematocrit level and other biochemical parameters were within normal limits. Notably, tumor markers were elevated: carcinoembryonic antigen (CEA) at 7.04 \u0026micro;g/L, cancer antigen 19\u0026thinsp;\u0026minus;\u0026thinsp;9 (CA19-9) at 82.6 U/mL, and cancer antigen 125 (CA125) at 106 U/mL.\u003c/p\u003e \u003cp\u003eA contrast-enhanced abdominopelvic CT examination conducted on the patient showed a predominantly mixed solid-cystic lesion, approximately 13x11x9 cm in size, arising from the left adnexal loge and extending to the midline at the umbilical level. The lesion displayed fat-fluid levels and calcifications. Its anterosuperior part contained a solid component about 5.5 cm thick at its widest, with lobulated margins and a heterogeneous internal texture. This component blurred the interface with adjacent intestinal attachments and extended into the surrounding peritoneal fat (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe patient underwent pelvic magnetic resonance imaging (MRI) to evaluate possible invasion into neighbouring tissues and organs. The MRI revealed a solid component with heterogeneous contrast enhancement and diffusion restriction, alongside areas demonstrating signal loss compatible with fat content and fat-fluid levels in T2 fat-suppressed sequences (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The lesion showed no clear evidence of invasive behaviour. Given the CT and MRI results, which were radiologically indicative of a mature cystic teratoma with malignant transformation, surgical intervention was scheduled.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eOvarian mass removed by unilateral salpingoophrectomy (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The ovarian mass evaluated by an experienced gynecopathologist during the operation, was reported as a mature cystic teratoma. The final histopathological examination revealed squamous cell carcinoma derived from the mature cystic teratoma. This unexpected outcome underscores the limitations of frozen section analysis in certain cases and the necessity for comprehensive tissue examination.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOvarian germ cell tumours (GCTs) are uncommon malignancies that derive from ovarian germ cells (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Among these, teratomas represent the most frequent germ cell tumour type, predominantly seen in younger women. Teratomas are classified into three histological variants: mature, immature, and monodermal teratomas (struma ovarii). The MCT subtype is the most common, accounting for 95% of teratomas and 10% of all ovarian germ cell tumours (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMCTs are distinctly bounded, encapsulated cystic tumours that encompass components from at least two germinal layers\u0026mdash;ectoderm, mesoderm, and endoderm\u0026mdash;featuring diverse tissue and organ components like hair, skin, neural structures, fat, sebaceous glands, and teeth (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMCTs rarely demonstrate malignant transformation, with an incidence rate ranging from 1.5-2% (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The predominant malignancy arising from such transformations is squamous cell carcinoma, comprising 80% of these cases, with other variations including adenocarcinoma, small cell carcinoma, malignant melanoma, and sarcoma (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Studies have shown that these transformations typically occur in postmenopausal women, and the mean age at diagnosis is reported to be 53.5 years (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The most frequent manifestations in squamous cell carcinoma cases originating from MCTs are abdominal pain (47.3%) and the presence of an abdominal mass (26.0%) (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn suspicious cases, preoperative radiologic evaluation plays a crucial role in anticipating malignant transformation and guiding surgical decision-making. Şahin et al. emphasized that tumor markers are not always correlated with tumor size (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). This suggests that malignancy risk is not solely size-dependent but also related to specific imaging features. In our case, radiological findings were key to raising suspicion for malignant transformation and directing the surgical approach. These tumours may exhibit a complex architecture featuring both cystic and solid components, reflecting their diverse tissue and organ content. This variability appearance can sometimes pose diagnostic challenges. In line with this, Pelayo et al. emphasized that although most mature cystic teratomas and serous cystadenomas are correctly classified by ultrasound, certain features\u0026mdash;especially the presence of solid components or acoustic shadows\u0026mdash;may lead to misclassification, underlining the importance of expert interpretation in radiological evaluation (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Typically identified as fatty, hyperechoic lesions during routine ultrasound (US) screenings, MCTs may show characteristic but not definitive signs such as the dot-dash sign, indicative of internal hair, and the tip of the iceberg sign, related to posterior acoustic attenuation. Often, their similar appearance to complex haemorrhagic cysts necessitates further evaluation using cross-sectional imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). These imaging techniques effectively visualize characteristics like fat-fluid levels, calcifications, and structural thickening. In cases like ours, CT findings of well-defined tumour margins, sizes over 10 cm, and cauliflower-like appearances might prompt concerns for malignant transformation. Moreover, MRI can accurately delineate the extent of a tumour\u0026rsquo;s malignant component, invasion, and metastasis with high sensitivity (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe primary treatment for MCTs with malignant changes is surgical intervention. Research has demonstrated that combining total hysterectomy and bilateral salpingo-oophorectomy with neoadjuvant chemotherapy markedly enhances survival. Moreover, the study highlighted that lymphadenectomy and omentectomy lack verified effectiveness in decreasing mortality. Additionally, the research reported no observable difference in outcomes between fertility-preserving and radical surgical approaches, and there was no established efficacy for postoperative radiotherapy in enhancing treatment results (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOvarian mature cystic teratomas are frequently occurring benign tumours that mainly impact young women. On occasion, these teratomas can malignantly transform, most commonly into squamous cell carcinoma, thereby elevating the risks of morbidity and mortality. Consequently, prompt diagnosis, diligent follow-up after treatment, and a comprehensive, interdisciplinary approach are essential in the management of these complications.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e: Furkan \u0026Ouml;zdem was responsible for the conception and design of the study, conducted the literature review, wrote the manuscript, and performed the critical review. S\u0026uuml;meyya Duran Kaymak contributed to the conception of the study, supervised the work, and participated in manuscript writing. Berna Turhan also contributed to the conception of the study, supervision, and manuscript writing. Similarly, Candost Hanedan played a role in the conception of the study, supervision, and manuscript writing. Sezgi Barlas and \u0026Ouml;zge Demirsoy contributed to the conception of the study and provided supervision. Rasime Pelin Kavak also contributed to the conception of the study and supervision.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e The authors declared that this study has received no financial support or funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e: All data contained in this study can be obtained from the corresponding author under reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompliance with Ethical Standards\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e Furkan \u0026Ouml;zdem, S\u0026uuml;meyya Duran Kaymak, Berna Turhan, Candost Hanedan, Sezgi Barlas, \u0026Ouml;zge Demirsoy and Rasime Pelin Kavak have read and approved the manuscript, and, subject to acceptance, authors will transfer copyright to the Publisher; there is no ethical problem or conflict of interest, and there has been no duplicate publication or submission elsewhere.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication:\u0026nbsp;\u003c/strong\u003eThe written informed consent was obtained from subjects and/or their legal guardians for publication\u0026nbsp;\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSt Louis, M., Mangal, R., Stead, T. S., Sosa, M., \u0026amp; Ganti, L. (2022). Ovarian Dermoid Tumor. Cureus, 14(7), e27233. https://doi.org/10.7759/cureus.27233\u003c/li\u003e\n\u003cli\u003eCong, L., Wang, S., Yeung, S. Y., Lee, J. H. S., Chung, J. P. W., \u0026amp; Chan, D. Y. L. (2023). Mature cystic teratoma: an integrated review. International Journal of Molecular Sciences, 24(7), 6141.\u003c/li\u003e\n\u003cli\u003eDeeksha, H. S., Pajai, S., Patel, D. J., Navalihiremath, V. U., \u0026amp; Jyotsna, G. (2024). Unraveling the Enigma: A Case Report on Unilateral Ovarian Dermoid Cyst. Cureus, 16(2).\u003c/li\u003e\n\u003cli\u003eSahin, H., Abdullazade, S., \u0026amp; Sanci, M. (2017). Mature cystic teratoma of the ovary: a cutting edge overview on imaging features. Insights into imaging, 8, 227-241.\u003c/li\u003e\n\u003cli\u003eMatalliotakis, M., Matalliotaki, C., Tsakiridis, I., Dagklis, T., Michos, G., Romanos, A., Krithinakis, K., \u0026amp; Kalogiannidis, I. A. (2024). Co-existence of Ovarian Teratomas With Other Gynecological Tumors. Cureus, 16(4), e58068. https://doi.org/10.7759/cureus.58068\u003c/li\u003e\n\u003cli\u003eMontebello, A., Maniscalco, N., Grech, M., Cuschieri, A., \u0026amp; Brockdorff, K. M. V. (2024). Squamous cell carcinoma of the ovary arising from a mature cystic teratoma associated with hypercalcaemia. British Journal of Hospital Medicine, 1-5.\u003c/li\u003e\n\u003cli\u003ePeluso, E., Edwards, W. F., \u0026amp; Janco, J. M. T. (2024). Metastatic squamous cell carcinoma arising from mature teratoma of the ovary: Description of multi-modality treatment including incorporation of adjuvant immunotherapy and maintenance PARP inhibitor therapy. Gynecologic Oncology Reports, 52, 101371.\u003c/li\u003e\n\u003cli\u003eLi, C., Zhang, Q., Zhang, S., Dong, R., Sun, C., Qiu, C., ... \u0026amp; Kong, B. (2019). Squamous cell carcinoma transformation in mature cystic teratoma of the ovary: a systematic review. BMC cancer, 19, 1-12.\u003c/li\u003e\n\u003cli\u003eSahin, F., Akt\u0026uuml;rk, E., G\u0026uuml;nkaya, O. S., \u0026Ouml;zdemir, S., Konal, M., Gen\u0026ccedil;, S., ... \u0026amp; Akbayir, O. (2023). Borderline ovarian tumors: twenty years of experience at a tertiary center. \u003cem\u003eAnatolian Current Medical Journal\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(3), 196-200.\u003c/li\u003e\n\u003cli\u003ePelayo, M., Sancho-Sauco, J., S\u0026aacute;nchez-Zurdo, J., Perez-Mies, B., Abarca-Mart\u0026iacute;nez, L., Cancelo-Hidalgo, M. J., ... \u0026amp; Pelayo-Delgado, I. (2023). Application of Ultrasound scores (subjective Assessment, simple rules Risk Assessment, ADNEX Model, O-RADS) to Adnexal masses of difficult classification. \u003cem\u003eDiagnostics\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e(17), 2785.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ovarian Mature Cystic Teratoma, Squamous Cell Carcinoma, Malignant Conversion, Ovarian Tumours","lastPublishedDoi":"10.21203/rs.3.rs-5661121/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5661121/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eOvarian mature cystic teratomas (MCTs) are the most prevalent benign ovarian tumors, with rare potential for malignant transformation, most commonly into squamous cell carcinoma. Accurate diagnosis is crucial for optimal management and prognosis.\u003c/p\u003e\u003ch2\u003eCase Presentation:\u003c/h2\u003e \u003cp\u003eA 27-year-old woman presented with a year-long history of intermittent abdominal and groin pain. Imaging studies, including contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), revealed a mixed solid-cystic lesion in the left adnexal region, consistent with an MCT exhibiting radiologic signs of malignancy. The patient underwent unilateral salpingo-oophorectomy, and intraoperative frozen section analysis suggested a mature cystic teratoma. However, definitive histopathological examination confirmed squamous cell carcinoma arising from the MCT. This case highlights the limitations of frozen section analysis in detecting malignancy.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eMalignant transformation of MCTs, though rare, poses significant diagnostic and therapeutic challenges. Comprehensive preoperative imaging and meticulous postoperative histopathological evaluation are essential for accurate diagnosis and effective management. This case underscores the importance of interdisciplinary collaboration in addressing complex gynecologic pathologies.\u003c/p\u003e","manuscriptTitle":"A Rare Case of Malignant Transformation: Squamous Cell Carcinoma Arising on the Basis of an Ovarian Mature Cystic Teratoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-15 01:21:38","doi":"10.21203/rs.3.rs-5661121/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accepted","date":"2025-04-24T14:04:12+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-22T14:07:29+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-13T18:38:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"107451301938563535547493936911270615552","date":"2025-04-13T18:35:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328604933449337270200072487326925768681","date":"2025-04-13T16:29:33+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-11T15:40:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"114742276402494884364002404906307226611","date":"2025-04-11T15:38:24+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-11T15:10:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-11T00:38:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Women's Health","date":"2025-04-09T19:24:51+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ba034e9c-a5c4-48b3-aa52-46106b0383e0","owner":[],"postedDate":"April 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-05-05T16:05:40+00:00","versionOfRecord":{"articleIdentity":"rs-5661121","link":"https://doi.org/10.1186/s12905-025-03755-7","journal":{"identity":"bmc-womens-health","isVorOnly":false,"title":"BMC Women's Health"},"publishedOn":"2025-05-02 15:57:37","publishedOnDateReadable":"May 2nd, 2025"},"versionCreatedAt":"2025-04-15 01:21:38","video":"","vorDoi":"10.1186/s12905-025-03755-7","vorDoiUrl":"https://doi.org/10.1186/s12905-025-03755-7","workflowStages":[]},"version":"v1","identity":"rs-5661121","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5661121","identity":"rs-5661121","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}