{"paper_id":"e604c3e0-4ea4-414a-9283-a60a5bc0a31c","body_text":"Review began\n 11/27/2025 \nReview ended\n 12/06/2025 \nPublished\n 12/08/2025\n© Copyright \n2025\nYagi et al. This is an open access article\ndistributed under the terms of the Creative\nCommons Attribution License CC-BY 4.0.,\nwhich permits unrestricted use, distribution,\nand reproduction in any medium, provided\nthe original author and source are credited.\nDOI:\n 10.7759/cureus.98762\nMassive Ovarian Edema Successfully Treated\nThrough Accurate Preoperative Diagnosis and\nLaparoscopic Conservative Surgery\nMarina Yagi \n, \nTakeshi Fukuda \n, \nTakuma Wada \n, \nMakoto Yamauchi \n, \nToshiyuki Sumi \n1.\n Department of Obstetrics and Gynecology, Osaka Metropolitan University Graduate School of Medicine, Osaka, JPN\nCorresponding author: \nTakeshi Fukuda, \ntfukuda@omu.ac.jp\nAbstract\nMassive ovarian edema (MOE) is a rare benign condition that causes marked ovarian enlargement due to\nstromal fluid accumulation and can mimic an ovarian neoplasm. Accurate preoperative diagnosis is essential\nto avoid unnecessary oophorectomy, especially in young women.\nA 26-year-old nulligravid woman presented with right lower abdominal pain. Ultrasonography showed a\nmarkedly enlarged right ovary with peripheral follicles and mottled hypoechoic areas. MRI demonstrated an\n85-mm enlarged ovary with high T2 signal intensity and multiple peripheral cysts, findings suggestive of\nMOE. Tumor markers were within normal limits. Based on characteristic imaging features and prior clinical\nexperience, MOE was strongly suspected preoperatively. Laparoscopy revealed a markedly enlarged ovary\nwith a 360-degree torsion. Following detorsion, the ovary decreased in size. A cortical incision revealed no\ntumorous lesion, and serous fluid leaked from the stroma. A wedge biopsy was performed, and\nhistopathology confirmed MOE. The postoperative course was uneventful, and follow-up ultrasonography\none month later showed complete return of the ovary to normal size.\nThis case illustrates the diagnostic value of characteristic ultrasonographic and MRI findings of MOE and\nhighlights the importance of clinical experience in avoiding unnecessary oophorectomy and achieving\nfertility-preserving management.\nCategories:\n Obstetrics/Gynecology, Radiology\nKeywords:\n conservative surgery, fertility preservation, laparoscopy, massive ovarian edema, ovarian torsion\nIntroduction\nMassive ovarian edema (MOE) is a rare, tumor-like gynecological condition characterized by marked\nenlargement of the ovary due to the accumulation of edematous fluid within the ovarian stroma, first\ndescribed by Kalstone et al. in 1969 \n[1]\n. This condition predominantly affects adolescents and young women,\nwith a mean reported age of approximately 20 years; however, both premenarcheal \n[2]\n and postmenopausal\nwomen \n[3]\n may also be affected. MOE is generally considered to result from partial or intermittent torsion of\nthe ovarian pedicle, leading to impaired venous and lymphatic drainage while preserving arterial inflow \n[1]\n. \nClinically and radiologically, MOE often mimics a solid ovarian neoplasm, creating a diagnostic challenge.\nUltrasonography and computed tomography may show nonspecific ovarian enlargement, whereas magnetic\nresonance imaging has been reported to reveal characteristic findings such as peripheral displacement of\nfollicles around a centrally edematous stroma-features that may assist in distinguishing this entity from true\novarian tumors \n[4,5]\n. Because MOE is a benign and potentially reversible condition, misdiagnosis may lead\nto unnecessary oophorectomy, resulting in avoidable loss of ovarian function. Fertility-preserving,\nconservative surgical management is therefore recommended whenever malignancy can be reasonably\nexcluded.\nAccurate preoperative recognition is essential, particularly in young women presenting with solid-appearing\novarian enlargement. The present report describes a case of MOE in a 26-year-old woman that was\nsuccessfully managed with conservative laparoscopic surgery following appropriate preoperative diagnosis.\nCase Presentation\nA 26-year-old nulligravid woman with no significant past medical or family history and without any\ngynecological symptoms other than right lower abdominal pain presented to her previous physician with\nright lower abdominal pain. Transvaginal ultrasonography performed at the prior clinic revealed a right\novarian mass, and she was subsequently referred to our hospital for further evaluation. At the initial visit,\ntransvaginal ultrasonography demonstrated an enlarged right ovary measuring 79.5 × 74.8 mm, with\nmultiple small cystic structures aligned along the inner margin and mottled hypoechoic areas within the\nparenchyma (Figure \n1\n).\n1\n1\n1\n1\n1\n \nOpen Access Case Report\nHow to cite this article\nYagi M, Fukuda T, Wada T, et al. (December 08, 2025) Massive Ovarian Edema Successfully Treated Through Accurate Preoperative Diagnosis\nand Laparoscopic Conservative Surgery. Cureus 17(12): e98762. \nDOI 10.7759/cureus.98762\n\nFIGURE\n 1: Transvaginal ultrasonography of both ovaries.\nThe image on the left shows the right ovary, measuring 79.5 × 74.8 mm, with multiple small cystic structures along\nthe inner margin and mottled hypoechoic areas within the parenchyma. Arrowheads indicate the small cystic\nstructures. The image on the right shows the normal left ovary, measuring 42.7 × 21.3 mm.\nPelvic magnetic resonance imaging (MRI) further revealed a 77.9 × 68.7 × 81.08 mm enlarged right ovary,\nagain showing numerous small peripheral cystic structures without any solid component. The left ovary was\nnormal in size (Figure \n2\n).\nFIGURE\n 2: Pelvic MRI findings.\n(A) T1-weighted sagittal image. (B) T2-weighted sagittal image. (C) T2-weighted axial image. The enlarged right\novary measures 77.9 × 68.7 × 81.0 mm and contains multiple peripheral ovarian follicles. The lesion is isointense\non T1-weighted imaging and hyperintense on T2-weighted imaging, consistent with edematous stroma.\nArrowheads indicate the small cystic structures.\nSerum tumor markers were within normal limits: CA125 was 12 U/mL (normal limits, ≤35 U/ml), CA19-9 was\n8 U/mL (normal limits, ≤37 U/ml), and carcinoembryonic antigen was <1.7 ng/mL (normal limits, <5 ng/ml).\nThe imaging findings were highly suggestive of MOE. Ultrasonography demonstrated a solid-appearing\nenlarged ovary with peripheral displacement of follicles and mottled hypoechoic areas consistent with\nstromal edema, while MRI showed a markedly enlarged ovary with edematous stroma exhibiting high signal\nintensity on T2-weighted images and follicles compressed toward the periphery by accumulated stromal\nfluid. Based on these characteristic radiologic features, MOE secondary to ovarian torsion was strongly\nsuspected rather than an ovarian neoplasm. However, because the patient continued to experience\nabdominal pain and a definitive diagnosis could not be established preoperatively, surgical intervention was\nplanned. Laparoscopic surgery revealed the right ovary enlarged to beyond the size of a goose’s egg, with a\n360-degree torsion of the ovarian pedicle (Figure \n3A\n). The left ovary appeared normal. After detorsion, a\ncortical incision was made to evaluate the internal structure. No tumorous lesion was identified; instead, the\novarian parenchyma appeared markedly edematous (Figure \n3B\n). As the incision deepened, transparent\nserous fluid leaked from the ovarian stroma. For diagnostic confirmation, a small portion of the right ovary\nwas resected by wedge resection, and hemostasis was secured. Notably, following detorsion and wedge\nresection, the swollen right ovary had already begun to decrease in size and had nearly returned to normal\ndimensions by the end of the procedure (Figure \n3C\n).\n \n2025 Yagi et al. Cureus 17(12): e98762. DOI 10.7759/cureus.98762\n2\n of \n6\n\nFIGURE\n 3: Intraoperative findings.\n(A) Markedly enlarged right ovary, exceeding the size of a goose’s egg, with a 360-degree torsion of the ovarian\npedicle. The arrowhead indicates the site of torsion. (B) After cortical incision of the right ovary. No tumorous\nlesion is observed; instead, the ovarian parenchyma appears markedly edematous, with serous fluid leaking from\nthe stroma. (C) End of surgery. Following detorsion and partial resection of the right ovary, the ovarian size has\ndecreased substantially and has nearly returned to normal.\nThe postoperative course was uneventful, and the patient was discharged on postoperative day four. The\nmacroscopic examination of the resected ovarian tissue revealed a diffusely swollen ovary with edematous\nstroma and no identifiable tumorous lesion (Figure \n4\n).\nFIGURE\n 4: Gross findings of the resected ovarian specimen.\nThe specimen exhibits diffuse stromal edema without a defined mass, and the cut surface is watery, consistent\nwith massive ovarian edema.\nHistopathological examination demonstrated preservation of normal follicular architecture with marked\nstromal edema, consistent with MOE (Figure \n5\n).\n \n2025 Yagi et al. Cureus 17(12): e98762. DOI 10.7759/cureus.98762\n3\n of \n6\n\nFIGURE\n 5: Histopathological findings of the resected portion of the right\novary (hematoxylin and eosin staining).\nNormal follicular architecture is preserved, and marked stromal edema is present. (A) Scale bar, 200 µm. (B)\nScale bar, 100 µm. (C) Scale bar, 50 µm.\nAt the one-month postoperative follow-up, transvaginal ultrasonography confirmed that the right ovary had\nreturned to normal size (Figure \n6\n).\nFIGURE\n 6: Follow-up transvaginal ultrasonography one month after\nsurgery.\nThe right ovary (left image) has decreased in size to 32.5 mm and returned to normal size.\nDiscussion\nMOE is an uncommon benign condition characterized by marked enlargement of the ovary due to the\naccumulation of stromal fluid while preserving normal follicular architecture. Since its first description in\n1969 \n[1]\n, MOE has remained a diagnostic challenge because its clinical and radiologic manifestations often\nmimic those of solid ovarian neoplasms. Most affected patients are adolescents or young women,\nhighlighting the importance of accurate diagnosis to avoid unnecessary oophorectomy and preserve fertility\n[6]\n.\nThe predominant mechanism proposed for MOE is partial or intermittent torsion of the ovarian pedicle,\nwhich impairs venous and lymphatic drainage while maintaining arterial inflow, ultimately leading to\nprogressive stromal edema without ischemic necrosis \n[1,7]\n. In the present case, a 360-degree torsion of the\nright ovarian pedicle was identified intraoperatively, supporting torsion as the precipitating factor.\nRadiologic evaluation plays a crucial role in preoperative diagnosis. Ultrasonography typically demonstrates\na solid-appearing enlarged ovary with multiple peripheral follicles \n[8]\n, whereas MRI shows high T2 signal\nintensity within the edematous stroma and peripheral compression of follicles \n[4,9]\n. These findings have\nbeen recognized as characteristic but are not exclusive to MOE, as they may overlap with those of ovarian\nfibroma, polycystic ovary, cystadenoma, and metastatic carcinoma \n[4,10]\n. In our patient, both\nultrasonography and MRI revealed classic findings of MOE, enabling preoperative suspicion of the diagnosis.\nFurthermore, preoperative suspicion of MOE was strengthened by the fact that our team had previously\nencountered and published a case of massive ovarian edema \n[5]\n, which enhanced our familiarity with its\ncharacteristic imaging and intraoperative features.\n \n2025 Yagi et al. Cureus 17(12): e98762. DOI 10.7759/cureus.98762\n4\n of \n6\n\nSurgical findings in MOE classically reveal a markedly enlarged ovary with edematous stroma and the cut\nsurfaces appear grey-white, watery, and gelatinous \n[1,7,11]\n. In our case, the right ovary not only exhibited\npronounced edema but also demonstrated dramatic reduction in size after detorsion and wedge resection, a\nfinding that further supports MOE as a reversible condition when promptly treated. This intraoperative\nshrinkage is a hallmark feature, as demonstrated in our previously reported case \n[5]\n, and may assist\nclinicians in confirming the diagnosis during surgery.\nThe management of MOE should prioritize ovarian preservation, particularly in young women. Historically,\nmisdiagnosis has led to unnecessary oophorectomy; however, growing awareness and improved imaging\nhave facilitated more conservative approaches. Importantly, a large review reported that among 177\npublished cases of MOE, 145 patients (81.9%) underwent adnexectomy and 12 patients (6.8%) underwent\nhysterectomy with bilateral salpingo-oophorectomy, whereas only 20 patients (11.3%) received conservative\ntreatment \n[6]\n. This striking imbalance highlights the strong tendency toward overtreatment and emphasizes\nthe need for heightened awareness of MOE as a benign, fertility-preserving condition. Wedge resection has\nbeen reported as a preferred treatment option for MOE \n[7]\n. In our patient, conservative laparoscopic surgery\nwith detorsion and diagnostic wedge resection was successful, and postoperative recovery was uneventful.\nFollow-up ultrasound confirmed complete restoration of ovarian morphology within one month, reinforcing\nthe suitability of fertility-sparing management.\nConclusions\nMOE is a rare but important clinical entity that can closely mimic ovarian neoplasm. Early recognition and\nfertility-preserving surgical management are crucial. The present case demonstrates the characteristic\nradiologic and intraoperative features of MOE and underscores the importance of considering this diagnosis\nin young women with ovarian enlargement and suspected torsion.\nAdditional Information\nAuthor Contributions\nAll authors have reviewed the final version to be published and agreed to be accountable for all aspects of the\nwork.\nConcept and design:\n  \nTakeshi Fukuda, Marina Yagi, Takuma Wada, Makoto Yamauchi, Toshiyuki Sumi\nAcquisition, analysis, or interpretation of data:\n  \nTakeshi Fukuda, Marina Yagi\nDrafting of the manuscript:\n  \nTakeshi Fukuda, Marina Yagi\nCritical review of the manuscript for important intellectual content:\n  \nTakeshi Fukuda, Takuma Wada,\nMakoto Yamauchi, Toshiyuki Sumi\nSupervision:\n  \nTakeshi Fukuda, Toshiyuki Sumi\nDisclosures\nHuman subjects:\n Informed consent for treatment and open access publication was obtained or waived by all\nparticipants in this study. \nConflicts of interest:\n In compliance with the ICMJE uniform disclosure form, all\nauthors declare the following: \nPayment/services info:\n All authors have declared that no financial support\nwas received from any organization for the submitted work. \nFinancial relationships:\n All authors have\ndeclared that they have no financial relationships at present or within the previous three years with any\norganizations that might have an interest in the submitted work. \nOther relationships:\n All authors have\ndeclared that there are no other relationships or activities that could appear to have influenced the\nsubmitted work.\nAcknowledgements\nDuring the preparation of this work, the authors used ChatGPT (GPT 5.1, by OpenAI) to enhance the\nreadability and proofread the English text. 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