The size of the endometrioid ovarian cyst according to ultrasound as a predictor of deep endometriosis and an indication for pelvic magnetic resonance imaging

DOI: 10.47026/2413-4864-2026-3-1-11

UDC: 618.14-002-007.61:616-073
BBC: 57.1

Alieva P.M., Solopova A.E., Dumanovskaya M.R., Smetnik A.A.

The size of the endometrioid ovarian cyst according to ultrasound as a predictor of deep endometriosis and an indication for pelvic magnetic resonance imaging

Keywords: ovarian endometrioma, deep endometriosis, transvaginal ultrasound examination, magnetic resonance imaging, predictor

Endometriosis is a widespread gynecological disease associated with chronic pelvic pain and infertility. The most clinically severe form is deep endometriosis, characterized by invasion of endometrioid foci to a depth of more than 5 mm. Ultrasound examination is a first-line method, but its diagnostic sensitivity in relation to deep endometriosis is limited. A number of studies indicate an association of endometrioid ovarian cysts with deep endometriosis forms, but these data are contradictory. It remains unclear whether the cyst itself or its size determines this relationship. The aim of the study was to evaluate the diagnostic value of the maximum linear size of the endometrioid ovarian cyst, measured by routine transvaginal ultrasound examination, as a predictor of deep endometriosis and to substantiate an objective criterion for performing magnetic resonance imaging of the pelvic organs. Materials and methods. A retrospective cohort study included 80 patients with verified external genital endometriosis operated at V.I. Kulakov National Research Medical Center for Obstetrics, Gynecology and Perinatology; the study was conducted in 2020–2023. Inclusion criteria: ultrasound examination (performed no later than 4 weeks prioir to performing magnetic resonance imaging), magnetic resonance imaging of pelvic organs and histological verification of the diagnosis. Deep endometriosis was diagnosed by magnetic resonance imaging based on the presence of infiltration foci greater than 5 mm involving the sacro-uterine ligaments, the rectovaginal septum, the bladder, ureters or intestines. Statistical processing included binary logistic regression and ROC analysis. Results. Deep endometriosis was found in 49 out of 80 patients (61.3%). Among 64 patients with endometrioid cysts, deep endometriosis was diagnosed in 37 (57.8%) of them and 12 (75%) out of 16 patients without endometrioid cysts were diagnosed with deep endometriosis. The average size of endometrioid cysts in the group with deep endometriosis was 4.76±1.24 cm, in the group without deep endometriosis – 2.74±1.95 cm (p = 0.001). Cyst size turned out to be the only statistically significant predictor of deep endometriosis: with an increase in size by 1 cm, the odds ratio increased to 8.83 (95% confidence interval 2.96–26.35; p < 0.01). The area under the ROC curve was 0.933. The optimal threshold value for the size of an endometrioid ovarian cyst is 3.5 cm (sensitivity 90.9%, specificity 85.7%). When the cyst size was ≥ 3.5 cm, the positive prognostic value reached 88.9%. Conclusions. The size of the endometrioid ovarian cyst ≥ 3.5 cm, determined by routine ultrasound examination, can serve as a clinically justified criterion for referring patients to magnetic resonance imaging of the pelvic organs in order to detect deep endometriosis.

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About authors

Alieva Patimat M.: Obstetrician-Gynecologist, Post-Graduate Student, Department of Gynecological Endocrinology, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov, Russia, Moscow (aalievapm@gmail.com; ORCID: https://orcid.org/0009-0007-1391-3211)

Solopova Alina E.: Doctor of Medical Sciences, Leading Researcher, Radiology Department, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov; Professor, Department of Obstetrics, Gynecology, Perinatology and Perinatal Medicine, I.M. Sechenov First Moscow State Medical University (Sechenovskiy University), Russia, Moscow (a_solopova@oparina4.ru; ORCID: https://orcid.org/0000-0003-4768-115X)

Dumanovskaya Madina R.: Candidate of Medical Sciences, Senior Researcher, Department of Gynecological Endocrinology, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov, Russia, Moscow (m_dumanovskaya@oparina4.ru; ORCID: https://orcid.org/0000-0001-7286-6047)

Smetnik Antonina A.: Candidate of Medical Sciences, Head of the Department of Gynecological Endocrinology, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov, Russia, Moscow (a_smetnik@oparina4.ru; ORCID: https://orcid.org/0000-0002-0627-3902)

Article link

Alieva P.M., Solopova A.E., Dumanovskaya M.R., Smetnik A.A. The size of the endometrioid ovarian cyst according to ultrasound as a predictor of deep endometriosis and an indication for pelvic magnetic resonance imaging [Electronic resource] // Acta medica Eurasica. – 2026. – №3. P. 1-11. – URL: https://acta-medica-eurasica.ru/en/single/2026/3/1/. DOI: 10.47026/2413-4864-2026-3-1-11.

Single article

Alieva P.M., Solopova A.E., Dumanovskaya M.R., Smetnik A.A.