Imaging features of complex solid and multicystic ovarian lesions: proposed algorithm for differential diagnosis

Influence of field strength on quantitative parameters and feature stability in the assessment of the ovaries using 1.5-T and 3-T MRI

BackgroundLittle is known of the influence of scanner field strength on quantitative diffusivity variables, especially kurtosis in healthy ovaries.PurposeTo evaluate the influence of scanner field strength on quantitative diffusion variables in pelvic MRI of the ovaries.Material and MethodsThis prospective, single-centre study consisted of repeated 1.5-T and 3-T examinations in 30 female volunteers (mean age=27.9 years, age range=20.3-45.2 years) from July 2017 to September 2019. Multi b-value DWI 0, 50, 100, 800, 1500, 2000 s/mm2 was acquired over three timepoints during the menstrual cycle. Ovaries were segmented at b = 1500 s/mm2. Median apparent diffusion coefficient (ADC) and advanced kurtosis parameters Dapp and Kapp were calculated. Statistical analysis was performed with the variations of diffusivity variables being compared between 1.5-T and 3-T MRI using a Mann-Whitney rank-sum test.ResultsMedian ADC and Dapp (µm²/ms) did not statistically differ. Median ADC were 1.509 (range=1.371-1.610), 1.619 (range=1.463-1.747), and 1.511 (range=1.423-1.639) at 1.5 T; 1.542 (range=1.428-1.682), 1.658 (range=1.510-1.806), and 1.572 (range=1.455-1.709) at 3 T (P = 0.14, 0.19, and 0.07), whereas median Dapp were 2.024 (range=1.913-2.152), 2.192 (range=2.010-2.327), and 2.045 (range=1.958-2.170) at 1.5 T; 2.013 (range=1.952-2.188), 2.179 (range=2.018-2.327), and 2.082 (range=1.959-2.194) at 3 T (P = 0.77, 0.99, and 0.34) for timepoints 1, 2, and 3, respectively. Statistical comparison of Kapp revealed significant differences for all timepoints: 0.629 (range=0.595-0.652), 0.604 (range=0.574-0.651), and 0.622 (range=0.581-0.664) at 1.5 T; 0.601 (range=0.563-0.626), 0.567 (range=0.526-0.633), and 0.599 (range=0.541-0.650) at 3 T (P < 0.001, 0.005, and 0.03).ConclusionDiffusivity mapping in the ovaries provides similar absolute median diffusion values, but statistically significant differences in absolute kurtosis values between 1.5 T and 3 T.

A giant ovarian atypical proliferative mucinous tumor in a young adult: A rare case report and review of the literature

INTRODUCTION AND IMPORTANCE

Ovarian atypical proliferative mucinous tumor (APMT) is a low-malignant or borderline tumor that originates from the ovary's surface epithelium. This tumor can grow to a massive size, causing abdominal distention, which can result in a variety of compression symptoms if it is not discovered early.

CASE PRESENTATION

A 23-year-old female presented with a chronic, gradually developing abdominal distention that had been persistent for a year. A large peritoneal cyst was suggested by an abdominal CT scan. A massive left ovarian tumor was discovered during an exploratory laparotomy. Salpingo-oophorectomy was performed, and the pathology report confirmed the diagnosis of APMT. No recurrence has been observed during a year of follow-up.

CLINICAL DISCUSSION

Diagnosis of ovarian APMBT involves clinical assessment, history, and symptoms of the patient. Imaging studies are useful in identifying these lesions. Ultrasound demonstrates a large, unilocular or multilocular cystic mass with thin septations. Further characterization requires an MRI or CT scan. Serum tumor markers such as CEA, CA-125, and β-hCG are helpful in diagnosing these lesions. The definitive diagnosis requires histopathological examination. Unilateral salpingo-oophorectomy is the mainstay of treatment. Adjuvant therapy is not required. Lifelong follow-up is essential, especially for fertility-sparing surgeries due to recurrence risk.

CONCLUSION

Due to the substantial overlap of clinicopathological characteristics with other tumors, accurate diagnosis of APMT can be difficult. Large tumor sizes may cause alarm for other pathologies such as cancer. The attending physician should be reassured with the imaging examinations, and the diagnosis is confirmed by the histopathology examination.

STAT3 mediates ECM stiffness-dependent progression in ovarian cancer

The treatment of ovarian cancer remains a medical challenge and its malignant progression is connected with obvious changes in both tissue and cell stiffness. However, the accurate mechanical-responsive molecules and mechanism remains unclear in ovarian cancer. Based on our previous results combined with the crucial regulatory role of STAT3 in the malignant progression of various cancer types, we want to investigate the relationship between STAT3 and matrix stiffness in ovarian cancer and further explore the potential mechanisms. Collagen-coated polyacrylamide gels (1, 6, and 60 kPa) were prepared to mimic soft or hard matrix stiffness. Western blotting, qRT-PCR, flow cytometry, IHC, EdU assays, and TEM were used to evaluate the effect of STAT3 in vitro under different matrix stiffnesses. Furthermore, a BALB/c nude mouse model was established to assess the relationship in vivo. Our results confirmed the differential expression of STAT3/p-STAT3 not only in normal and malignant ovarian tissues but also under different matrix stiffnesses. Furthermore, we verified that STAT3 was a mechanically responsive gene both in vitro and in vivo, and the mechanical response was carried out by altering the migration-related molecules (TNFAIP1) and adhesion-related molecules (LPXN, CNN3). The novel findings suggest that STAT3, a potential therapeutic target for clinical diagnosis and treatment, is a mechanically responsive gene that responds to matrix stiffness, particularly regulation in migration and adhesion in the progression of ovarian cancer.

A Predictive Model for Initial Platinum-Based Chemotherapy Efficacy in Patients with Postoperative Epithelial Ovarian Cancer Using Tissue-Derived Small Extracellular Vesicles

Epithelial ovarian cancer (EOC) is an often-fatal malignancy marked by the development of resistance to platinum-based chemotherapy. Thus, accurate prediction of platinum drug efficacy is crucial for strategically selecting postoperative interventions to mitigate the risks associated with suboptimal therapeutic outcomes and adverse effects. Tissue-derived extracellular vesicles (tsEVs), in contrast to their plasma counterparts, have emerged as a powerful tool for examining distinctive attributes of EOC tissues. In this study, 4D data-independent acquisition (DIA) proteomic sequencing was performed on tsEVs obtained from 58 platinum-sensitive and 30 platinum-resistant patients with EOC. The analysis revealed a notable enrichment of differentially expressed proteins that were predominantly associated with immune-related pathways. Moreover, pivotal immune-related proteins (IRPs) were identified by LASSO regression. These factors, combined with clinical parameters selected through univariate logistic regression, were used for the construction of a model employing multivariate logistic regression. This model integrated three tsEV IRPs, CCR1, IGHV_35 and CD72, with one clinical parameter, the presence of postoperative residual lesions. Thus, this model could predict the efficacy of initial platinum-based chemotherapy in patients with EOC post-surgery, providing prognostic insights even before the initiation of chemotherapy.

Multiparametric Ultrasound Examination in Tumor-Like Formations of the Ovaries

Properly diagnosed tumor-like formations of the ovaries facilitate the correct selection of patients who may not require surgery, or choose surgery with minimal access if such intervention is required. Subjective assessment of the features of tumor-like formations with the help of ultrasound diagnostics, including compression elastography, proved to be highly effective in the differential diagnosis of bulky ovarian formations. All tumor-like formations have their sonographic features that allow making a reliable diagnosis of a particular formation. The article reveals data on the diagnostic significance of multiparametric ultrasound imaging in the detection of ovarian tumor-like formations. A detailed sonographic picture of tumor-like formations in B-mode, color, and pulse Doppler mode and compression sonoelastography mode was analyzed. This examination was especially relevant for women of reproductive age, as it depended on the further tactics of treatment of each patient. For all types of tumor-like formations ovaries, a qualitative feature was determined - elastotype on the Ueno scale and the index of stiffness (Strain Ratio) - a quantitative indicator. Follicular cysts, endometrioid and periovarian cysts were found to belong to the 0 elastotype. Cysts of the corpus luteum belonged to the II elastotype on the Ueno scale. The lowest values of the stiffness index were seen in follicular and periovarian cysts, and the highest value was observed in endometrioid cysts. Our results have shown that ultrasound examination of ovarian tumors is an accurate and highly informative method.

Ultra-High-b-Value Kurtosis Imaging for Noninvasive Tissue Characterization of Ovarian Lesions

Background MRI with contrast material enhancement is the imaging modality of choice to evaluate sonographically indeterminate adnexal masses. The role of diffusion-weighted MRI, however, remains controversial. Purpose To evaluate the diagnostic performance of ultra-high-b-value diffusion kurtosis MRI in discriminating benign and malignant ovarian lesions. Materials and Methods This prospective cohort study evaluated consecutive women with sonographically indeterminate adnexal masses between November 2016 and December 2018. MRI at 3.0 T was performed, including diffusion-weighted MRI (b values of 0-2000 sec/mm²). Lesions were segmented on b of 1500 sec/mm² by two readers in consensus and an additional independent reader by using full-lesion segmentations on a single transversal slice. Apparent diffusion coefficient (ADC) calculation and kurtosis fitting were performed. Differences in ADC, kurtosis-derived ADC (D_app), and apparent kurtosis coefficient (K_app) between malignant and benign lesions were assessed by using a logistic mixed model. Area under the receiver operating characteristic curve (AUC) for ADC, D_app, and K_app to discriminate malignant from benign lesions was calculated, as was specificity at a sensitivity level of 100%. Results from two independent reads were compared. Histopathologic analysis served as the reference standard. Results A total of 79 ovarian lesions in 58 women (mean age ± standard deviation, 48 years ± 14) were evaluated. Sixty-two (78%) lesions showed benign and 17 (22%) lesions showed malignant histologic findings. ADC and D_app were lower and K_app was higher in malignant lesions: median ADC, D_app, and K_app were 0.74 µm²/msec (range, 0.52-1.44 µm²/msec), 0.98 µm²/msec (range, 0.63-2.12 µm²/msec), and 1.01 (range, 0.69-1.30) for malignant lesions, and 1.13 µm²/msec (range, 0.35-2.63 µm²/msec), 1.45 µm²/msec (range, 0.44-3.34 µm²/msec), and 0.65 (range, 0.44-1.43) for benign lesions (P values of .01, .02, < .001, respectively). AUC for K_app of 0.85 (95% confidence interval: 0.77, 0.94) was higher than was AUC from ADC of 0.78 (95% confidence interval: 0.67, 0.89; P = .047). Conclusion Diffusion-weighted MRI by using quantitative kurtosis variables is superior to apparent diffusion coefficient values in discriminating benign and malignant ovarian lesions and might be of future help in clinical practice, especially in patients with contraindication to contrast media application. © RSNA, 2020 Online supplemental material is available for this article.

Magnetic Resonance Imaging of Gynecological Malignancies: Role in Personalized Management

Gynecological malignancies are a leading cause of mortality and morbidity in women and pose a significant health problem around the world. Currently used staging systems for management of gynecological malignancies have unresolved issues, the most important being recommendations on the use of imaging. Although not mandatory as per the International Federation of Gynecology and Obstetrics recommendations, preoperative cross-sectional imaging is strongly recommended for adequate and optimal management of patients with gynecological malignancies. Standardized disease-specific magnetic resonance imaging protocols help assess disease spread accurately and avoid pitfalls. Multiparametric imaging holds promise as a roadmap to personalized management in gynecological malignancies. In this review, we will highlight the role of magnetic resonance imaging in cervical, endometrial, and ovarian carcinomas.

Usefulness of transabdominal real-time sonoelastography in the evaluation of ovarian lesions: preliminary results

OBJECTIVE

We aim to evaluate and describe the tissue elasticity characteristics of various ovarian lesions with sonoelastography.

METHODS

35 patients (age range 16-85 years; mean age 40.8 years) underwent sonoelastography and later MRI. Histopathological confirmation of all lesions was carried out, except eight of endometriomas and six of septated cysts which were confirmed on MRI and follow-up ultrasonography. Strain ratios and elastogram patterns were recorded. Lesions were classified into three groups (Group 1: cystic lesions, Group 2: benign tumours and Group 3: malignant lesions) and findings were compared between groups for both observers. Interobserver agreement was analyzed. Optimal cut-off values for strain ratios were achieved with receiver operating characteristic curve analysis.

RESULTS

Ovarian endometriomas and complex cystic lesions were observed hard on elastograms with high strain ratios, and malignant lesions were observed mostly soft with very small strain ratios. Benign tumours had average tissue stiffness, observed harder than the malignant lesions, and strain ratios ranged from 4 to 14. The differences in patterns and strain ratios between groups were statistically significant (p < 0.05 for both observers).

CONCLUSION

Our study revealed that malignant ovarian lesions have softer tissue property than benign lesions and cystic lesions in terms of elastogram patterns and strain ratios.

ADVANCES IN KNOWLEDGE

Most ovarian lesions contain solid and cystic parts which make the malignant and benign lesions look similar on imaging modalities. Using real-time sonoelastography as an adjunct to other imaging modalities may improve the differentiation of malignant ovarian lesions from benign lesions.