Huge endometrioma mimicking ovarian malignancy : a case report

Huge endometrioma mimicking ovarian malignancy : a case report | 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 Huge endometrioma mimicking ovarian malignancy : a case report Yu Chen Hsu, Keng-Fu Hsu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4127108/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Endometriosis is a very common disease, yet sometimes it is hard to be diagnosed. Typical symptoms include pelvic pain and infertility. However, it could present with a variety of symptoms depending on different type of endometriosis. There are also a variety of imaging findings indicative of endometriosis with varying sizes and locations. Huge ovarian mass accompanied with mass-effect symptoms was not usual in typical endometriosis, and may be considered as ovarian malignancy at initial diagnosis. Case presentation A middle-aged woman presented with dyspnea, lower leg edema, and abdominal dullness for 2-3 years. Laboratory exam showed severe anemia, severe hypokalemia, impaired renal function, and metabolic acidosis. Abdominal sonography and computed tomography (CT) showed huge pelvic mass 35x33x28cm with solid part. Exploratory laparotomy revealed right ovarian endometrioma and endometriosis of sigmoid colon. After operation, she had much less dyspnea and abdominal dullness, while renal function was only partially improved with bilateral ureteral stents remained in place. Conclusion We presented a case report of huge endometrioma mimicking ovarian malignancy. The atypical symptoms and image findings were uncommon for endometriosis. We thus shared this case for help further differential diagnosis of huge pelvic mass. Endometrioma endometriosis ovarian malignancy case report Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Endometriosis is a very common disease, accounting for approximately 10% of reproductive-age women. Despite its high prevalence, endometriosis could be sometimes hard to be diagnosed. The most common symptoms were pelvic pain and infertility; however, it is a systematic disease which could have various and nonspecific manifestations ( 1 ). There was also difficulty for early diagnosis due to non-specific biomarkers, lack of awareness, and stigma or symptom normalization. Timing of diagnosis could be after seven-physician visiting before diagnosis, or after incidental diagnosis during operation for other indications ( 2 ). There are three main types of endometriosis, including superficial peritoneal disease, endometrioma, and deep infiltrating endometriosis. The most common type is endometrioma, and the usual size of endometrioma mostly less than 6 cm ( 3 ). Typical characteristic of endometrioma under sonography is the classic ground glass echogenicity. The containing viscous proteinaceous and hemorrhagic products, which may be revealed as avascular solid nodules or papillary projections under sonography, could also mimic as malignancy ( 4 ). The case scenario and clinical examination made our tentative diagnosis and surgical planning difficult. We thus presented this case of huge endometrioma mimicking ovarian malignancy, providing us a differential diagnosis among patients with huge pelvic mass. Case presentation A G0P0, 49-year-old female with history of myomectomy 12 years ago came to our hospital for help. She had abdominal fullness for 2–3 years, and had dyspnea, lower leg edema, and decreased urinary output for recent 2 months (Fig. 1 ). She denied abdominal pain, vaginal bleeding, or increased vaginal discharge. Her menstruation cycle was regular, with no dysmenorrhea or hypermenorrhea. At arrival, vital signs were relatively stable. Electrocardiogram (EKG) showed sinus tachycardia. Physical exam showed abdominal dullness and lower limb pitting edema 3+. Cervix was hard to be identified under pelvic examination and fixed parametrium was also noted. Laboratory analysis showed serum hemoglobin level, 4.8 g/dl (range, 11.0–15.0 g/dl); serum potassium level, 2.5 mmol/L (range, 3.5–5.1 mmol/L); serum creatinine level, 10.84 mg/dl (range, 0.50–0.90 mg/dl); estimated glomerular filtration rate 3.8, and serum gas pH, 7.23 (range 7.32–7.45); serum gas bicarbonate level, 13.5 mmol/L. Abdominal CT scan revealed huge pelvic cystic mass 35x33x28cm with solid part, favoring gynecological origin, and bilateral grade 4 hydronephrosis (Fig. 2 ). Due to post-renal obstructive uropathy, bilateral percutaneous nephrostomy was performed. Intermittent hemodialysis was also performed. After blood transfusion, fluid balance and electrolyte correction, she was arranged for exploratory laparotomy of the pelvic mass. During operation, the huge pelvic mass favored right ovarian mass with 15300cc tumor content was noted (Fig. 3 ). There was severe adhesion between pelvic mass and urinary bladder, pelvic mass and sigmoid colon. Uterus was completely imbedded in the pelvic mass. Subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. Frozen section of right ovarian mass showed extensive infarction type necrosis and no visible malignant cells. Biopsy of adhesion site, including omentum, and partial sigmoid colon resection and re-anastomosis were performed. Final pathology revealed right ovarian endometrioma with extensive infarction and focal suppurative inflammation (Fig. 4 ). There was endometriosis over sigmoid colon, yet not over the omentum. After operation, there was no immediate complications. The patient’s body weight decreased from 74 to 50 kg. She had much less abdominal fullness, dyspnea, and lower leg edema. After the operation for one year, the patient's renal function showed partial improvements with serum creatinine level, 4.00 mg/dl, (range, 0.50–0.90 mg/dl) and estimated glomerular filtration rate 11.9, while bilateral ureteral stents remained in place. Discussion and Conclusions Endometrioma was common among reproductive age women. Size of endometrioma varies, usually ranged from 1 to 6 cm. Huge ovarian endometrioma with size over 10-15cm was rare, and was reported with only isolated case reports ( 5 ). Reviewing previous case reports, our case was the third largest endometrial cyst. The largest case was a diabetic and hypertensive woman developing progressive abdominal distension for 8 years, found with 65 × 55 × 50 cm endometrial cyst and 214 liters tumor contents ( 6 ). The second case was a morbid-obese woman having dyspnea and anuria for 3 days and was diagnosed as left ovarian endometrioma 50x30x15cm ( 7 ). Excluding the two extremely giant endometrial cyst, our case was the largest endometrioma complicated with severe post-renal acute kidney injury. There are a variety of symptoms among patients with endometriosis, while the classic symptoms were pelvic pain and infertility. Initial diagnosis may be delayed due to lack of awareness or symptom normalization. Additionally, as the size of endometrioma became larger and larger, symptoms usually became predominantly mass effect of endometrioma, making preoperative diagnosis more challenging. According to prior case report, a G0P0, 29-year-old female with chronic dysmenorrhea developed with abdominal distension and dyspnea for one month. However, endometriosis was not diagnosed until she underwent exploratory laparotomy for the huge pelvic mass ( 8 ). Another case report showed a 33-year-old nullipara woman presented with recurrent abdominal pain, abdominal swelling, and difficulty in breathing for 3 years. Definite diagnosis could not be done, even laparoscopic multiple biopsies showed only chronic inflammation. It was not until the patient underwent exploratory laparotomy that huge endometriosis was diagnosed ( 3 ). In our case, the patient denied dysmenorrhea or chronic pelvic pain. She was unmarried and denied infertility. The symptoms including abdominal distension, dyspnea on exertion, bilateral leg edema, and decreased urinary output, all occurred in recent 1–3 years. The clinical scenarios of this patient did not give us a clue of endometriosis; instead, malignancy should be ruled out. For the diagnostic image of endometrioma, the first-line non-invasive modality was transvaginal ultrasound. Typical features included a unilocular cyst with internal homogeneous low-level echoes without solid component or internal vascularity. Nevertheless, atypical findings included a fluid-fluid level and an avascular internal nodule or papillary projection, may be presented in almost 50% of endometriotic women ( 9 ). Under abdominal computed tomography, there was no typical feature of endometrioma, ranging from simple cyst to complex cystic mass ( 10 ). Although magnetic resonance imaging (MRI) was sufficient for diagnosis of endometrioma with specificity greater than 90% ( 10 ), it was not clinically considered as the first-line modality. In our case, the echogenicity may correspond to endometrioma. However, the large size and solid component of the pelvic mass on ultrasound and abdominal CT made diagnosis challenging, mimicking malignancy. In conclusions, this is a case of ovarian endometriosis mimicking malignancy. The clinical picture of presentations and images made us confuse for the final diagnosis. It also gave us a different view of endometriosis and let us consider another differential diagnose when evaluating a huge pelvic mass. Abbreviations CT: computed tomography; EKG: electrocardiogram; MRI: magnetic resonance imaging Declarations Ethics approval and consent to participate Not applicable Consent for publication Written informed consent was obtained from the patient for publication of this case report and any accompanying images. Availability of data and materials All other clinical data will be available upon request. Competing interests All authors certify that they have no competing interests to declare that they are relevant to the content of this article. Funding No funding was obtained for this study. Authors' contributions YCH cojoined the operation, reviewed the literature, collected data, drafted the manuscript, and reviewed and revised the manuscript for submission. KFH planned and performed the preoperative assessment, the operation, and the postoperative follow-up, and supervised the manuscript writings. All authors read and approved the final manuscript. Acknowledgments Not applicable References Taylor HS, Kotlyar AM, Flores VA. Endometriosis is a chronic systemic disease: clinical challenges and novel innovations. The Lancet. 2021;397(10276):839-52. Zondervan KT, Becker CM, Missmer SA. Endometriosis. New England Journal of Medicine. 2020;382(13):1244-56. Yahya A, Mustapha A, Kolawole AO, Oguntayo AO, Bello N, Aliyu HO, et al. Giant Ovarian Endometrioma: A Case Report. J West Afr Coll Surg. 2021;11(4):41-4. Quesada J, Härmä K, Reid S, Rao T, Lo G, Yang N, et al. Endometriosis: A multimodal imaging review. Eur J Radiol. 2023;158:110610. Mishra TS, Singh S, Jena SK, Mishra P, Mishra L. Giant Endometrioma of the Ovary: A Case Report. Journal of Endometriosis and Pelvic Pain Disorders. 2016;8(2):71-4. Shah AA, Soomro NA, Talib RK, Sadhayo AN, Soomro SA. Giant intraabdominal endometrial cyst. J Coll Physicians Surg Pak. 2014;24(6):438-40. Sakpal SV, Patel C, Chamberlain RS. Near lethal endometriosis and a massive (64 kg) endometrioma: case report and review of the literature. Clin Exp Obstet Gynecol. 2009;36(1):49-52. Capaccione KM, Levin M, Tchabo N, Darcey J, Amorosa J. Massive endometrioma presenting with dyspnea and abdominal symptoms. Radiol Case Rep. 2017;12(4):741-5. Collins BG, Ankola A, Gola S, McGillen KL. Transvaginal US of Endometriosis: Looking Beyond the Endometrioma with a Dedicated Protocol. RadioGraphics. 2019;39(5):1549-68. Tran-Harding K, Nair RT, Dawkins A, Ayoob A, Owen J, Deraney S, et al. Endometriosis revisited: an imaging review of the usual and unusual manifestations with pathological correlation. Clinical Imaging. 2018;52:163-71. Additional Declarations No competing interests reported. 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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-4127108","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":281855473,"identity":"c7421dfc-f5cb-4a41-b949-9735fcd2602f","order_by":0,"name":"Yu Chen Hsu","email":"","orcid":"","institution":"National Cheng Kung University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"Chen","lastName":"Hsu","suffix":""},{"id":281855474,"identity":"37f84536-c1a8-4ba1-af99-ceaa7a4876fd","order_by":1,"name":"Keng-Fu Hsu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9ElEQVRIiWNgGAWjYDCC++cfPkioYGBgYwfxDoCIBAJabvAwG3w4A9TCjKzlAH4tbJIz24AMorXw3e49bMw7b5s8HzMD24MfZw4z8LPnGDB/bMOtRfLOucTHvNtuG7YxM7Ab9tw4zCDZ88aA4SAeLQYHEoyNgVoYgVrYpBk+HGYwuJED1LINrxYzad45t+3hWuwJarmRYyY5s+F2IkQL0GEGEgS0SJ45lmzw4djt5DZmxjbJnjPpPBJnnhUcOPsPtxa+480HHyTU3Lad3958TOLHMWs5/vbkjQ8qzuDWggQYG0AkD4g4QJSGUTAKRsEoGAU4AQC6NliTV+5/bAAAAABJRU5ErkJggg==","orcid":"","institution":"National Cheng Kung University Hospital","correspondingAuthor":true,"prefix":"","firstName":"Keng-Fu","middleName":"","lastName":"Hsu","suffix":""}],"badges":[],"createdAt":"2024-03-19 04:14:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4127108/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4127108/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53266839,"identity":"6ad6dcbd-2df4-480e-a13d-8033de4dba06","added_by":"auto","created_at":"2024-03-22 15:44:37","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1852754,"visible":true,"origin":"","legend":"\u003cp\u003eSevere distended abdomen.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-4127108/v1/e7d567a5a243d50df3ae03fb.png"},{"id":53266837,"identity":"e5011fd1-cddd-4fb6-a552-40a068ea9263","added_by":"auto","created_at":"2024-03-22 15:44:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":603569,"visible":true,"origin":"","legend":"\u003cp\u003eImage of preoperative abdominal computed tomography scan (a) transverse section showed huge pelvic mass with bilateral hydronephrosis (b) sagittal section showed huge pelvic mass with solid part.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-4127108/v1/42bc898986b394ae23d0fa04.png"},{"id":53266838,"identity":"c887522c-9a30-4284-a405-341a2513f8c0","added_by":"auto","created_at":"2024-03-22 15:44:37","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1733553,"visible":true,"origin":"","legend":"\u003cp\u003eGross picture of right ovarian cystic mass.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-4127108/v1/a2c8367d15a3e17e87cfa2ac.png"},{"id":53266840,"identity":"098e2889-fe02-4f6e-b89a-101aec09a78d","added_by":"auto","created_at":"2024-03-22 15:44:38","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2059250,"visible":true,"origin":"","legend":"\u003cp\u003ePathology of right ovarian cystic mass showed ovarian endometrioma with extensive infarction.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-4127108/v1/a0ecaffabdb076ea016b3c70.png"},{"id":53854416,"identity":"49ddc2c4-9bae-4754-83a9-81c6ea69b876","added_by":"auto","created_at":"2024-04-01 10:50:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":7033355,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4127108/v1/4e99b6d8-d88c-47ca-9668-b706322a3d5b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Huge endometrioma mimicking ovarian malignancy : a case report","fulltext":[{"header":"Background","content":"\u003cp\u003eEndometriosis is a very common disease, accounting for approximately 10% of reproductive-age women. Despite its high prevalence, endometriosis could be sometimes hard to be diagnosed. The most common symptoms were pelvic pain and infertility; however, it is a systematic disease which could have various and nonspecific manifestations (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). There was also difficulty for early diagnosis due to non-specific biomarkers, lack of awareness, and stigma or symptom normalization. Timing of diagnosis could be after seven-physician visiting before diagnosis, or after incidental diagnosis during operation for other indications (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThere are three main types of endometriosis, including superficial peritoneal disease, endometrioma, and deep infiltrating endometriosis. The most common type is endometrioma, and the usual size of endometrioma mostly less than 6 cm (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Typical characteristic of endometrioma under sonography is the classic ground glass echogenicity. The containing viscous proteinaceous and hemorrhagic products, which may be revealed as avascular solid nodules or papillary projections under sonography, could also mimic as malignancy (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe case scenario and clinical examination made our tentative diagnosis and surgical planning difficult. We thus presented this case of huge endometrioma mimicking ovarian malignancy, providing us a differential diagnosis among patients with huge pelvic mass.\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA G0P0, 49-year-old female with history of myomectomy 12 years ago came to our hospital for help. She had abdominal fullness for 2\u0026ndash;3 years, and had dyspnea, lower leg edema, and decreased urinary output for recent 2 months (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e). She denied abdominal pain, vaginal bleeding, or increased vaginal discharge. Her menstruation cycle was regular, with no dysmenorrhea or hypermenorrhea. At arrival, vital signs were relatively stable. Electrocardiogram (EKG) showed sinus tachycardia. Physical exam showed abdominal dullness and lower limb pitting edema 3+. Cervix was hard to be identified under pelvic examination and fixed parametrium was also noted. Laboratory analysis showed serum hemoglobin level, 4.8 g/dl (range, 11.0\u0026ndash;15.0 g/dl); serum potassium level, 2.5 mmol/L (range, 3.5\u0026ndash;5.1 mmol/L); serum creatinine level, 10.84 mg/dl (range, 0.50\u0026ndash;0.90 mg/dl); estimated glomerular filtration rate 3.8, and serum gas pH, 7.23 (range 7.32\u0026ndash;7.45); serum gas bicarbonate level, 13.5 mmol/L. Abdominal CT scan revealed huge pelvic cystic mass 35x33x28cm with solid part, favoring gynecological origin, and bilateral grade 4 hydronephrosis (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Due to post-renal obstructive uropathy, bilateral percutaneous nephrostomy was performed. Intermittent hemodialysis was also performed. After blood transfusion, fluid balance and electrolyte correction, she was arranged for exploratory laparotomy of the pelvic mass.\u003c/p\u003e \u003cp\u003eDuring operation, the huge pelvic mass favored right ovarian mass with 15300cc tumor content was noted (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e). There was severe adhesion between pelvic mass and urinary bladder, pelvic mass and sigmoid colon. Uterus was completely imbedded in the pelvic mass. Subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy were performed. Frozen section of right ovarian mass showed extensive infarction type necrosis and no visible malignant cells. Biopsy of adhesion site, including omentum, and partial sigmoid colon resection and re-anastomosis were performed. Final pathology revealed right ovarian endometrioma with extensive infarction and focal suppurative inflammation (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e). There was endometriosis over sigmoid colon, yet not over the omentum. After operation, there was no immediate complications. The patient\u0026rsquo;s body weight decreased from 74 to 50 kg. She had much less abdominal fullness, dyspnea, and lower leg edema. After the operation for one year, the patient's renal function showed partial improvements with serum creatinine level, 4.00 mg/dl, (range, 0.50\u0026ndash;0.90 mg/dl) and estimated glomerular filtration rate 11.9, while bilateral ureteral stents remained in place.\u003c/p\u003e"},{"header":"Discussion and Conclusions","content":"\u003cp\u003eEndometrioma was common among reproductive age women. Size of endometrioma varies, usually ranged from 1 to 6 cm. Huge ovarian endometrioma with size over 10-15cm was rare, and was reported with only isolated case reports (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Reviewing previous case reports, our case was the third largest endometrial cyst. The largest case was a diabetic and hypertensive woman developing progressive abdominal distension for 8 years, found with 65 \u0026times; 55 \u0026times; 50 cm endometrial cyst and 214 liters tumor contents (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The second case was a morbid-obese woman having dyspnea and anuria for 3 days and was diagnosed as left ovarian endometrioma 50x30x15cm (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Excluding the two extremely giant endometrial cyst, our case was the largest endometrioma complicated with severe post-renal acute kidney injury.\u003c/p\u003e \u003cp\u003eThere are a variety of symptoms among patients with endometriosis, while the classic symptoms were pelvic pain and infertility. Initial diagnosis may be delayed due to lack of awareness or symptom normalization. Additionally, as the size of endometrioma became larger and larger, symptoms usually became predominantly mass effect of endometrioma, making preoperative diagnosis more challenging. According to prior case report, a G0P0, 29-year-old female with chronic dysmenorrhea developed with abdominal distension and dyspnea for one month. However, endometriosis was not diagnosed until she underwent exploratory laparotomy for the huge pelvic mass (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Another case report showed a 33-year-old nullipara woman presented with recurrent abdominal pain, abdominal swelling, and difficulty in breathing for 3 years. Definite diagnosis could not be done, even laparoscopic multiple biopsies showed only chronic inflammation. It was not until the patient underwent exploratory laparotomy that huge endometriosis was diagnosed (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn our case, the patient denied dysmenorrhea or chronic pelvic pain. She was unmarried and denied infertility. The symptoms including abdominal distension, dyspnea on exertion, bilateral leg edema, and decreased urinary output, all occurred in recent 1\u0026ndash;3 years. The clinical scenarios of this patient did not give us a clue of endometriosis; instead, malignancy should be ruled out.\u003c/p\u003e \u003cp\u003eFor the diagnostic image of endometrioma, the first-line non-invasive modality was transvaginal ultrasound. Typical features included a unilocular cyst with internal homogeneous low-level echoes without solid component or internal vascularity. Nevertheless, atypical findings included a fluid-fluid level and an avascular internal nodule or papillary projection, may be presented in almost 50% of endometriotic women (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Under abdominal computed tomography, there was no typical feature of endometrioma, ranging from simple cyst to complex cystic mass (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Although magnetic resonance imaging (MRI) was sufficient for diagnosis of endometrioma with specificity greater than 90% (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e), it was not clinically considered as the first-line modality. In our case, the echogenicity may correspond to endometrioma. However, the large size and solid component of the pelvic mass on ultrasound and abdominal CT made diagnosis challenging, mimicking malignancy.\u003c/p\u003e \u003cp\u003eIn conclusions, this is a case of ovarian endometriosis mimicking malignancy. The clinical picture of presentations and images made us confuse for the final diagnosis. It also gave us a different view of endometriosis and let us consider another differential diagnose when evaluating a huge pelvic mass.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCT: computed tomography; EKG: electrocardiogram; MRI: magnetic resonance imaging\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Consent for publication\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for publication of this case report and any accompanying images.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Availability of data and materials\u003c/p\u003e\n\u003cp\u003eAll other clinical data will be available upon request.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Competing interests\u003c/p\u003e\n\u003cp\u003eAll authors certify that they have no competing interests to declare that they are relevant to the content of this article.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Funding\u003c/p\u003e\n\u003cp\u003eNo funding was obtained for this study.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Authors\u0026apos; contributions\u003c/p\u003e\n\u003cp\u003eYCH cojoined the operation, reviewed the literature, collected data, drafted the manuscript, and reviewed and revised the manuscript for submission. KFH planned and performed the preoperative assessment, the operation, and the postoperative follow-up, and supervised the manuscript writings. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Acknowledgments\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eTaylor HS, Kotlyar AM, Flores VA. Endometriosis is a chronic systemic disease: clinical challenges and novel innovations. The Lancet. 2021;397(10276):839-52.\u003c/li\u003e\n\u003cli\u003eZondervan KT, Becker CM, Missmer SA. Endometriosis. New England Journal of Medicine. 2020;382(13):1244-56.\u003c/li\u003e\n\u003cli\u003eYahya A, Mustapha A, Kolawole AO, Oguntayo AO, Bello N, Aliyu HO, et al. Giant Ovarian Endometrioma: A Case Report. J West Afr Coll Surg. 2021;11(4):41-4.\u003c/li\u003e\n\u003cli\u003eQuesada J, H\u0026auml;rm\u0026auml; K, Reid S, Rao T, Lo G, Yang N, et al. Endometriosis: A multimodal imaging review. Eur J Radiol. 2023;158:110610.\u003c/li\u003e\n\u003cli\u003eMishra TS, Singh S, Jena SK, Mishra P, Mishra L. Giant Endometrioma of the Ovary: A Case Report. Journal of Endometriosis and Pelvic Pain Disorders. 2016;8(2):71-4.\u003c/li\u003e\n\u003cli\u003eShah AA, Soomro NA, Talib RK, Sadhayo AN, Soomro SA. Giant intraabdominal endometrial cyst. J Coll Physicians Surg Pak. 2014;24(6):438-40.\u003c/li\u003e\n\u003cli\u003eSakpal SV, Patel C, Chamberlain RS. Near lethal endometriosis and a massive (64 kg) endometrioma: case report and review of the literature. Clin Exp Obstet Gynecol. 2009;36(1):49-52.\u003c/li\u003e\n\u003cli\u003eCapaccione KM, Levin M, Tchabo N, Darcey J, Amorosa J. Massive endometrioma presenting with dyspnea and abdominal symptoms. Radiol Case Rep. 2017;12(4):741-5.\u003c/li\u003e\n\u003cli\u003eCollins BG, Ankola A, Gola S, McGillen KL. Transvaginal US of Endometriosis: Looking Beyond the Endometrioma with a Dedicated Protocol. RadioGraphics. 2019;39(5):1549-68.\u003c/li\u003e\n\u003cli\u003eTran-Harding K, Nair RT, Dawkins A, Ayoob A, Owen J, Deraney S, et al. Endometriosis revisited: an imaging review of the usual and unusual manifestations with pathological correlation. Clinical Imaging. 2018;52:163-71.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Endometrioma, endometriosis, ovarian malignancy, case report","lastPublishedDoi":"10.21203/rs.3.rs-4127108/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4127108/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground\u003c/p\u003e\n\u003cp\u003eEndometriosis is a very common disease, yet sometimes it is hard to be diagnosed. Typical symptoms include pelvic pain and infertility. However, it could present with a variety of symptoms depending on different type of endometriosis. There are also a variety of imaging findings indicative of endometriosis with varying sizes and locations. Huge ovarian mass accompanied with mass-effect symptoms was not usual in typical endometriosis, and may be considered as ovarian malignancy at initial diagnosis.\u003c/p\u003e\n\u003cp\u003eCase presentation\u003c/p\u003e\n\u003cp\u003eA middle-aged woman presented with dyspnea, lower leg edema, and abdominal dullness for 2-3 years. Laboratory exam showed severe anemia, severe hypokalemia, impaired renal function, and metabolic acidosis. Abdominal sonography and computed tomography (CT) showed huge pelvic mass 35x33x28cm with solid part. Exploratory laparotomy revealed right ovarian endometrioma and endometriosis of sigmoid colon. After operation, she had much less dyspnea and abdominal dullness, while renal function was only partially improved with bilateral ureteral stents remained in place.\u003c/p\u003e\n\u003cp\u003eConclusion\u003c/p\u003e\n\u003cp\u003eWe presented a case report of huge endometrioma mimicking ovarian malignancy. The atypical symptoms and image findings were uncommon for endometriosis. We thus shared this case for help further differential diagnosis of huge pelvic mass.\u003c/p\u003e","manuscriptTitle":"Huge endometrioma mimicking ovarian malignancy : a case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-22 15:44:33","doi":"10.21203/rs.3.rs-4127108/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b713d51d-225c-496d-bbcb-f20c7aad911e","owner":[],"postedDate":"March 22nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-04-10T07:58:33+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-22 15:44:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4127108","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4127108","identity":"rs-4127108","version":["v1"]},"buildId":"B-jG_2CBjPDmsCi4Wdhf-","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}