Ki-67 expression levels in mature cystic teratomas and ovarian cystadenomas: morphological characterization of proliferative activity
Ibragimova U.D., Asaturova A.V., Kozachenko I.F., Badlaeva A.S., Rogozhina A.S., Adamyan L.V.
Benign ovarian tumors occur significantly more frequently than malignant tumors. Distinguishing between benign, borderline, and malignant ovarian neoplasms is crucial, as they have substantially different clinical and biological profiles and require distinct management strategies. The Ki-67 index, a universal marker of cellular proliferation, reflects the level of mitotic activity within the tumor tissue.
Objective. To evaluate the proliferative activity of cells in mature cystic teratomas and benign cystadenomas of the ovary using immunohistochemical assessment of the Ki-67 index.
Materials and methods. This study enrolled 189 patients aged 18–45 years with histologically confirmed benign ovarian tumors (mature cystic teratomas and cystadenomas). Standard histological examination and immunohistochemical staining with monoclonal antibodies against Ki-67 were performed to quantify the percentage of immunopositive nuclei within distinct tissue components of each tumor. Continuous variables are summarized as mean ± standard deviation (SD).
Results. All tumors examined exhibited markedly low levels of proliferative activity. The mean Ki-67 index was 8.9% in the epithelium of mature cystic teratomas, 0.4% in glial inclusions of teratomas, and 1.1% in the cystadenoma epithelium. The Ki-67 index in the epithelium of mature cystic teratomas was higher than that in cystadenoma epithelium and the glial component of teratomas.
Conclusion. Mature cystic teratomas and ovarian cystadenomas are characterized by low proliferation activity. The Ki-67 index reflects the distinctive cellular activity within the various tissue components of these tumors and may serve as a morphological indicator of their biological behavior.
Authors' contributions. Adamyan L.V., Asaturova A.V., Kozachenko I.F. – conception and design of the study; Asaturova A.V., Ibragimova U.D., Kozachenko I.F., Badlaeva A.S., Rogozhina A.S. – data collection and processing; Asaturova A.V., Ibragimova U.D. – statistical analysis; Ibragimova U.D., Asaturova A.V., Kozachenko I.F. – drafting of the manuscript; Adamyan L.V. – editing of the manuscript.
Conflicts of interest. The authors have no conflicts of interest to declare.
Funding. There was no funding for this study.
Ethical Approval. The study was reviewed and approved by the Research Ethics Committee of the V.I. Kulakov NMRC for OG&P, Ministry of Health of Russia.
Patient Consent for Publication. All patients provided informed consent for the publication of their data.
Authors' Data Sharing Statement. The data supporting the findings of this study are available upon request from the corresponding author after approval from the principal investigator.
For citation: Ibragimova U.D., Asaturova A.V., Kozachenko I.F., Badlaeva A.S., Rogozhina A.S., Adamyan L.V.
Ki-67 expression levels in mature cystic teratomas and ovarian cystadenomas:
morphological characterization of proliferative activity.
Akusherstvo i Ginekologiya/Obstetrics and Gynecology. 2026; (5): 133-139 (in Russian)
https://dx.doi.org/10.18565/aig.2026.59
Keywords
Ki-67
immunohistochemistry
proliferation index
mature cystic ovarian teratoma
ovarian cystadenoma
benign ovarian tumors
References
- Samaddar J.B., Barua M., Dutta Pal R., Mandal S., Samaddar D., Goswami B.K. Clinicopathological spectrum of ovarian neoplasms with a special emphasis on risk of malignancy index – a single institutional study. Asian J. Med. Sci. 2025; 16(9): 122-9. https://dx.doi.org/10.71152/ajms.v16i9.4713
- Mustafin C., Vesnin S., Turnbull A., Dixon M., Goltsov A., Goryanin I. Diagnostics of ovarian tumors in postmenopausal patients. Diagnostics (Basel). 2022; 12(11): 2619. https://dx.doi.org/10.3390/diagnostics12112619
- Aher K.D., Gadhire M., Bhosle A., Agarwal N. Giant mature cystic teratoma of the ovary mimicking a 36-week pregnancy in a 14-year-old female. Int. J. Res. Med. Sci. 2025; 13(12): 5539-42. https://dx.doi.org/10.18203/2320-6012.ijrms20253993
- Mordecai O.G., Oboma Y.I., Teme R. Immunocytochemistry profiling of ovarian cysts: a review of its clinical utility, future direction, and challenges. Tumor Discovery. 2025; 4(1): 14-26. https://dx.doi.org/10.36922/td.5369
- Singh N., Kamath S.M. Ki-67 immunostaining in epithelial ovarian tumors with clinicopathological correlation. Int. J. Med. Res. Health Sci. 2022; 11(5): 19-26.
- Dewi I.G.A.S.M., Susraini A.A.A.N., Ekawati N.P. HER2/neu and Ki-67 as prognostic factors in serous type ovarian carcinoma. Bali Med. J. 2020; 9(2): 567-71. https://doi.org/10.15562/bmj.v9i2.1926
- Basak B., Mondal S.K., Debnath S. WT1, Bcl-2, Ki-67 and Her2/Neu as diagnostic and prognostic immunomarkers in ovarian serous and endometrioid carcinoma. Int. J. Clin. Diagn. Pathol. 2020; 3(3): 153-7. https://dx.doi.org/10.33545/pathol.2020.v3.i3c.273
- ALgarsh H., Abusaida H., Torjman F. The correlate between argyrophilic nucleolar organizer region stain and Ki-67 immunohistochemistry in diagnostic breast cancer. Iberoam J. Med. 2020; 2(4): 285-92. https://dx.doi.org/10.5281/ZENODO.4043776
- Qasim Y.A., Saeed S.Z., Rashid I.M. Immunohistochemical study of P53 and Ki 67 expression in surface epithelial tumor of the ovary. Saudi J. Pathol. Microbiol. 2017; 2(3): 52-9. https://dx.doi.org/10.21276/sjpm.2017.2.3.3
- Zayyan M.S. Risk factors for ovarian cancer. In: Lasfar A., Cohen-Solal K., eds. Tumor progression and metastasis. 2020: 75-102.
- Zhang S., Zhang Y., Zhang X., Yang X., Liu L., Liu J. et al. Diagnostic extended usefulness of RMI: comparison of four risk of malignancy index in preoperative differentiation of borderline ovarian tumors and benign ovarian tumors. J. Ovarian Res. 2019; 12(1): 87. https://dx.doi.org/10.1186/s13048-019-0568-3
- Remnant L., Kochanova N.Y., Reid C., Cisneros-Soberanis F., Earnshaw W.C. The intrinsically disorderly story of Ki-67. Open Biol. 2021; 11(8): 210120. https://dx.doi.org/10.1098/rsob.210120
- Cong L., Wang S., Yeung S.Y., Lee J.H.S., Chung J.P.W., Chan D.Y.L. Mature cystic teratoma: an integrated review. Int. J. Mol. Sci. 2023; 24(7): 6141. https://dx.doi.org/10.3390/ijms24076141
- Cao Y., Wang B., Jia A.R., Li X., Yang L., Jia Z. Mature cystic teratoma of the ovary with a grossly visible, completely developed intestinal loop: a case report and review of the literature. Medicine (Baltimore). 2023; 102(26): e34081. https://dx.doi.org/10.1097/MD.0000000000034081
- Zhang J., He L., Yang L., Wang J., Wei L., Ma X., Jiang L. Ovarian collision tumor consisting of sclerosing stromal tumor and mature cystic teratoma complicated with Meigs syndrome: a case report. Oncol. Lett. 2022; 24(6): 443. https://dx.doi.org/10.3892/ol.2022.13563
- Elansary M.F.A.A., Alkafaji H.A., Al-Hilli N.M. Diagnostic evaluation of immunohistochemical expression of p16 and Ki67 in ovarian serous neoplasms. Iraqi Postgrad. Med. J. 2023; 22(2): 183-91. https://dx.doi.org/10.52573/IPMJ.2023.180588
- Li X., Tang X., Zhuo W. Malignant transformation of ovarian teratoma responded well to immunotherapy after failed chemotherapy: A case report. Ann. Palliat. Med. 2021; 10(7): 8499-505. https://dx.doi.org/10.21037/apm-20-2429
- Chai Y., Woo C.G., Kim J.Y., Kim C.J., Khang S.K., Kim J. et al. Diagnostic significance of cellular neuroglial tissue in ovarian immature teratoma. J. Pathol. Transl. Med. 2017; 51(1): 49-55. https://dx.doi.org/10.4132/jptm.2016.09.19
- Hongo-Kohama M., Kurata A., Hashimoto H., Fujita K., Horiuchi H., Nagao T., Kuroda M. Vascular smooth muscle cell maturation stage and Ki-67 index are diagnostic biomarkers for pathologic grade of ovarian teratoma. Int. J. Gynecol. Pathol. 2017; 36(6): 582-92. https://dx.doi.org/10.1097/PGP.0000000000000373
- Iemura Y., Yamada Y., Hirata M., Kataoka T.R., Minamiguchi S., Haga H. Histopathological characterization of the neuroglial tissue in ovarian teratoma associated with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis. Pathol. Int. 2018; 68(12): 677-84. https://dx.doi.org/10.1111/pin.12732
- Sardar K., Singh J., Tirkey S. Ki67 immunoexpression in ovarian tumours. IOSR J. Dent. Med. Sci. 2018; 17(2): 34-7. https://dx.doi.org/10.9790/0853-1702163437
- Yu N., Wang N., Liu Y.F., Li Y.Y., Zhang T.G. Expression and clinical significance of Ki-67, E-cadherin, and mesothelin in serous borderline ovarian tumors. Eur. J. Gynaecol. Oncol. 2017; 38(1): 85-90.
- Shiravani Z., Najib F.S., Momtahan M., Robati M., Hajisafari Tafti M., Namazi N. Are ovarian dermoid cysts should be always considered benign? A case series study of different malignant transformation. Indian J. Surg. Oncol. 2020; 11(Suppl 2): 156-8. https://dx.doi.org/10.1007/s13193-020-01159-7
- Öcal İ., Demir S. Prognostic value of Ki67 in borderline mucinous ovarian tumors. Med. J. SDU. 2023; 30(1): 123-9. https://dx.doi.org/10.17343/sdutfd.1187197
Received 17.02.2026
Accepted 20.03.2026
About the Authors
Ummusalimat D. Ibragimova, PhD student, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of Russia, 117997, Russia, Moscow, Ac. Oparin str., 4, amintaeva_umm@mail.ru, https://orcid.org/0009-0008-6984-7193Alexandra V. Asaturova, Dr. Med. Sci., Head of the 1st Pathological Anatomical Department, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of Russia, 117997, Russia, Moscow, Ac. Oparin str., 4, Associate Professor, Department of Pathological Anatomy and
Clinical Pathological Anatomy, Institute of Biology and Pathobiology (IBPCh), Pirogov Russian National Research Medical University, Ministry of Health of Russia,
a.asaturova@gmail.com, https://orcid.org/0000-0001-8739-5209
Irena F. Kozachenko, Dr. Med. Sci., Leading Researcher, Obstetrician-Gynecologist, Gynecological Department, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of the Russia, 117997, Russia, Moscow, Ac. Oparin str., 4, irenakozachenko@rambler.ru,
https://orcid.org/0000-0003-1822-9164
Alina S. Вadlaeva, Senior Researcher, Pathologist, 1st Department of Pathology, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of Russia, 117997, Russia, Moscow, Ac. Oparin str., 4; Associate Professor, Department of Pathological Anatomy and Clinical Pathological Anatomy, Institute of Biology and Pathobiology (IBPCh), Pirogov Russian National Research Medical University, Ministry of Health of Russia,
https://orcid.org/0000-0001-5223-9767
Aleksandra S. Rogozhina, Junior Researcher, Pathologist, 1st Department of Pathology, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of Russia, 117997, Russia, Moscow, Ac. Oparin str., 4, https://orcid.org/0009-0009-6244-1219
Leila V. Adamyan, Academician of the Russian Academy of Sciences, Dr. Med. Sci., Professor, Deputy Director for Research, Academician V.I. Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, Ministry of Health of Russia, 117997, Russia, Moscow, Ac. Oparin str., 4; Chief Specialist in Gynecology of the Ministry of Health of Russia; Head of the Department of Reproductive Medicine and Surgery of the Faculty of Postgraduate Education, Russian University of Medicine, Ministry of Health of Russia, adamyanleila@gmail.com, https://orcid.org/0000-0002-3253-4512
Corresponding author: Ummusalimat D. Ibragimova, amintaeva_umm@mail.ru
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