The limited oncogenic potential of unilocular adnexal cysts: A systematic review and meta-analysis

ACR Appropriateness Criteria® Clinically Suspected Adnexal Mass, No Acute Symptoms: 2023 Update

Asymptomatic adnexal masses are commonly encountered in daily radiology practice. Although the vast majority of these masses are benign, a small subset have a risk of malignancy, which require gynecologic oncology referral for best treatment outcomes. Ultrasound, using a combination of both transabdominal, transvaginal, and duplex Doppler technique can accurately characterize the majority of these lesions. MRI with and without contrast is a useful complementary modality that can help characterize indeterminate lesions and assess the risk of malignancy is those that are suspicious. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Imaging of a Pelvic Mass: Uterine

The most common origin of a non-uterine pelvic mass is from the ovary. Ultrasound is the initial imaging modality of choice, additional imaging with computed tomography (CT) and/or magnetic resonance imaging (MRI) is performed in selected cases. Adnexal masses are also encountered as incidental findings during ultrasound, CT or MRI. Many of the adnexal masses that are surgically removed are benign. For optimal outcome and cost effective management, noninvasive risk stratification of such adnexal masses is necessary when discovered incidentally or when identified in a patient with a clinically detected pelvic mass. The American College of Radiology Ovarian-Adnexal Reporting Data System is a pattern-based scoring system for adnexal masses imaged with ultrasound and MRI, which assists clinicians to guide in the appropriate management based on evidence-based risk categories. Non-ovarian and non-uterine pelvic masses include fallopian tube abnormalities, paraovarian cysts, peritoneal inclusion cysts, and rare causes include masses that arise from the gastrointestinal tract or the sacrum. To distinguish non-ovarian masses from an ovarian tumor, a critical step is to identify a normal appearing ovary separate from the pelvic mass. This may be challenging in the post-menopausal woman with an atrophic ovary. MRI is a useful adjunctive modality in such cases. Extraovarian masses typically displace pelvic side wall vasculature medially, compress, encase or medially displace the ureters.

Nomogram based on the O-RADS for predicting the malignancy risk of adnexal masses with complex ultrasound morphology

OBJECTIVE

The accurate preoperative differentiation of benign and malignant adnexal masses, especially those with complex ultrasound morphology, remains a great challenge for junior sonographers. The purpose of this study was to develop and validate a nomogram based on the Ovarian-Adnexal Reporting and Data System (O-RADS) for predicting the malignancy risk of adnexal masses with complex ultrasound morphology.

METHODS

A total of 243 patients with data on adnexal masses with complex ultrasound morphology from January 2019 to December 2020 were selected to establish the training cohort, while 106 patients with data from January 2021 to December 2021 served as the validation cohort. Univariate and multivariate analyses were used to determine independent risk factors for malignant tumors in the training cohort. Subsequently, a predictive nomogram model was developed and validated in the validation cohort. The calibration, discrimination, and clinical net benefit of the nomogram model were assessed separately by calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Finally, we compared this model to the O-RADS.

RESULTS

The O-RADS category, an elevated CA125 level, acoustic shadowing and a papillary projection with color Doppler flow were the independent predictors and were incorporated into the nomogram model. The area under the ROC curve (AUC) of the nomogram model was 0.958 (95% CI, 0.932-0.984) in the training cohort. The specificity and sensitivity were 0.939 and 0.893, respectively. This nomogram also showed good discrimination in the validation cohort (AUC = 0.940, 95% CI, 0.899-0.981), with a sensitivity of 0.915 and specificity of 0.797. In addition, the nomogram model showed good calibration efficiency in both the training and validation cohorts. DCA indicated that the nomogram was clinically useful. Furthermore, the nomogram model had higher AUC and net benefit than the O-RADS.

CONCLUSION

The nomogram based on the O-RADS showed a good predictive ability for the malignancy risk of adnexal masses with complex ultrasound morphology and could provide help for junior sonographers.

Spectrum of Ovarian Incidentalomas: Diagnosis and Management

Incidental ovarian lesions are asymptomatic lesions that are accidentally discovered during a CT or MRI examinations that involves the pelvic cavity or during a routine obstetric ultrasound study. Incidental ovarian masses are usually benign with a very low risk of malignancy yet underlying malignant pathology may be discovered during the diagnostic work-up of these lesions. Suspicion of malignancy is directly correlating with the increase in the patient's age, the increase in the size of the lesion, the presence of the solid components or thick septa and a high color scale of the ovarian mass. Following standard reporting and management protocols are essential to choose the proper work-up of these lesions to avoid unnecessary additional imaging and operative intervention. In this article, we will provide a review of the characteristic imaging features of some incidental and yet commonly encountered ovarian lesions. We will also summarize the recently published algorithms that are important for consistent reporting and standard management of these lesions.

Diagnostic accuracy and inter-observer reliability of the O-RADS scoring system among staff radiologists in a North American academic clinical setting

PURPOSE

The objective of this study is to evaluate the diagnostic accuracy, interobserver variability, and common lexicon pitfalls of the ACR O-RADS scoring system among staff radiologists without prior experience to O-RADS.

MATERIALS AND METHODS

After independent review of the ACR O-RADS publications and 30 training cases, three fellowship-trained, board-certified staff radiologists scored 50 pelvic ultrasound exams using the O-RADS system. The diagnostic accuracy and area under receiver operating characteristic were analyzed for each reader. Overall agreement and pair-wise agreement between readers were also analyzed.

RESULTS

Excellent specificities (92 to 100%), NPVs (92 to 100%), and variable sensitivities (72 to 100%), PPVs (66 to 100%) were observed. Considering O-RADS 4 and O-RADS 5 as predictors of malignancy, individual reader AUC values range from 0.94 to 0.98 (p < 0.001). Overall inter-reader agreement for all 3 readers was "very good," k = 0.82 (0.73 to 0.90, 95% CI, p < 0.001). Pair-wise agreement between readers were also "very good," k = 0.86-0.92. 14 out of 150 lesions were misclassified, with the most common error being down-scoring of a solid lesion with irregular outer contours.

CONCLUSION

Even without specific training, experienced ultrasound readers can achieve excellent diagnostic performance and high inter-reader reliability with self-directed review of guidelines and cases. The study highlights the effectiveness of ACR O-RADS as a stratification tool for radiologists and supports its continued use in practice.

Growth Rate of Ovarian Serous Cystadenomas and Cystadenofibromas

OBJECTIVES

We analyzed growth rates of benign ovarian serous cystadenomas and cystadenofibromas to understand what percentage would show a volume doubling time (DT) of less than 3 years, between 3 and 5 years, or greater than 5 years.

METHODS

We retrospectively reviewed pathology records (January 1, 2014, to June 30, 2019) to find all surgically excised ovarian serous cystadenomas and cystadenofibromas. Imaging records were then reviewed to identify those that had been confidently identified with ultrasound imaging, magnetic resonance imaging, or computed tomography at least twice before surgical removal, with at least a 60-day interval between studies. Three orthogonal measurements were recorded on the first and last imaging studies on which the mass was detected, with volume calculations by the prolate formula (product of 3 measurements multiplied by 0.52). The volume DT was calculated and grouped into 1 of 5 categories: (1) DT of less than 1 year; (2) DT of 1 to 3 years; (3) DT of 3 to 5 years; (4) DT of 5 to 10 years; and (5) no growth (any mass with a DT >10 years or showing a decrease in volume).

RESULTS

A total of 102 of 536 cystadenomas and 44 of 227 cystadenofibromas met inclusion criteria. Of the 146 tumors, 40 (27.4%) had a DT of less than 1 year; 38 (26.0%) had a DT of 1 to 3 years; 22 (15.1%) had a DT of 3 to 5 years; 10 (6.8%) had a DT of 5 to 10 years; and 36 (24.7%) showed no growth.

CONCLUSIONS

A total of 53.4% of ovarian serous cystadenomas/cystadenofibromas have a DT of less than 3 years; 15.1% have a DT between 3 and 5 years; and 31.5% have a DT of greater than 5 years or show no growth.

Benign Ovarian Cysts with Raised CA-125 Levels: Do We Need to Evaluate the Fallopian Tubes?

Objectives  It is not clearly known whether some benign (simple) ovarian cysts can convert into cancerous cysts. Size of cyst and wall abnormalities do predict the potentiality of malignancy. Not many studies have been done to explore the malignant potential of large-sized (> 5 cm) unilocular ovarian cysts without wall abnormalities. This study evaluated the correlation between ultrasonographic size of benign ovarian cysts and carbohydrate antigen 125 (CA-125) levels. Methodology  Sixty (60) premenopausal women were recruited for the study preoperatively, based on transvaginal ultrasound (TVUS) findings present in the case record sheet received along with the CA-125 sample in the biochemistry laboratories. Those cases with elevated CA-125 levels were selected, where patients had unilocular ovarian cysts without wall abnormalities. CA-125 was done using ECLIA methodology (Cobas e411, Germany). Statistical correlation was calculated between the ovarian cyst size and CA-125 levels using Spearman's Rho coefficient. Results  Mean age group of subjects were 29.7 ± 7.3 years and mean value of CA-125 (normal < 35 IU/mL) was found to be increased: 118.0 ± 147.1 IU/mL so was the mean diameter of cysts (cut off ≤ 5 cm): 48.6 ± 59.8 cm. No correlation was found between CA-125 levels and volume of ovarian cyst ( r = 0.005, p = 0.680) for all subjects. Conclusions  The lack of correlation between size of ovarian cysts and CA-125 levels provides a hint that the ovarian cyst epithelium does not directly express CA-125 and it may come from sites like the fallopian tube. Thus, raised level of CA-125 in benign ovarian cyst should be followed-up more closely, demanding assessment of fallopian tubes for early diagnosis of ovarian cancer. Also, algorithms can be explored to include size of ovarian cyst and CA 125 levels to predict ovarian cancer.

Size threshold for follow-up of postmenopausal adnexal cysts: 1 cm versus 3 cm

OBJECTIVES

To assess 3 cm size threshold for follow-up of simple cysts in postmenopausal women.

MATERIALS AND METHODS

Radiology information system was retrospectively queried for "US pelvis complete" over 8 years in women > 50 years, with keywords ovarian cyst, adnexal cyst, ovarian mass, cystic mass, cystic neoplasm, ovarian neoplasm, and ovarian mass. Premenopausal women were excluded. Cysts, were classified as ≤ 1 cm, 1-3 cm, 3-5 cm, and ≥ 7 cm. Largest cysts on each ovary was recorded. EMR and imaging archives were reviewed for assessing size, stability duration, and surgical records. Descriptive statistics and confidence interval were performed.

RESULTS

4388 patients met the initial search criteria. 919 cysts in 896 women (age: 50-91 years, mean: 61.5 years) were identified. We found 162 cysts ≤ 1 cm, 352 1-3 cm, 296 3-7 cm , and 51 ≥ 7 cm cysts. 127 patients with 1-3 cm cysts had no follow-up. Final analysis of 225 1-3 cm cysts included 203 ovarian and 22 paraovarian cysts (average size = 1.95 cm (1.1-3.0 cm)). 103 ovarian cysts had less than 2 years, and 100 cysts had more than 2 years follow-up. All except one ovarian cyst were stable for the entire duration of their follow-up (Mean duration of follow-up 5.4 years) (0.3%, 95% CI 0.0-0.05). 40 cysts resolved. One simple cyst increased in size (followed over 3.25 years) without suspicious imaging features and benign on surgery.

CONCLUSION

1-3 cm cysts represented the most common size range (> 40%) in postmenopausal women, majority of which are stable over follow-up with benign outcome. 3 cm size threshold is appropriate for simple cyst follow-up in postmenopausal women.

The Abnormal Ovary: Evolving Concepts in Diagnosis and Management

Ovarian lesions are common and require a consistent approach to diagnosis and management for best patient outcomes. In the past 20 years, there has been an evolution in the approach to abnormal ovarian lesions, with increasing emphasis on reducing surgery for benign disease, standardizing terminology, assessing risk of malignancy through use of evidence-based scoring systems, and triaging suspicious abnormalities to dedicated oncology centers. This article provides an evidence-based review of how these changes in diagnosis and management of ultrasound-detected abnormal ovarian lesions have occurred. Current recommended practices are summarized. The current literature on transvaginal screening for ovarian cancer also is reviewed and summarized.

O-RADS US Risk Stratification and Management System: A Consensus Guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee

The Ovarian-Adnexal Reporting and Data System (O-RADS) US risk stratification and management system is designed to provide consistent interpretations, to decrease or eliminate ambiguity in US reports resulting in a higher probability of accuracy in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. It was developed by an international multidisciplinary committee sponsored by the American College of Radiology and applies the standardized reporting tool for US based on the 2018 published lexicon of the O-RADS US working group. For risk stratification, the O-RADS US system recommends six categories (O-RADS 0-5), incorporating the range of normal to high risk of malignancy. This unique system represents a collaboration between the pattern-based approach commonly used in North America and the widely used, European-based, algorithmic-style International Ovarian Tumor Analysis (IOTA) Assessment of Different Neoplasias in the Adnexa model system, a risk prediction model that has undergone successful prospective and external validation. The pattern approach relies on a subgroup of the most predictive descriptors in the lexicon based on a retrospective review of evidence prospectively obtained in the IOTA phase 1-3 prospective studies and other supporting studies that assist in differentiating management schemes in a variety of almost certainly benign lesions. With O-RADS US working group consensus, guidelines for management in the different risk categories are proposed. Both systems have been stratified to reach the same risk categories and management strategies regardless of which is initially used. At this time, O-RADS US is the only lexicon and classification system that encompasses all risk categories with their associated management schemes.

Imaging and Differential Diagnosis of Ovarian Cancer

Ovarian cancer is the seventh most common cancer affecting women. Despite advances in cancer control and healthcare in general, mortality from ovarian cancer remains unacceptably high due to diagnosis at an advanced stage of the disease. The 5-year survival rate is 47.4% because a majority of ovarian cancers are diagnosed when advanced. Only 14.9% of ovarian cancers are diagnosed when localized where the survival rate is 92.3%. Mortality rate reduction by screening has not been proven in women at an average risk for ovarian cancer. Ultrasound remains the primary modality for assessment of ovarian tumors. The need for standardizing terminology is critical for optimal assessment of the risk of malignancy in an ovarian tumor. The international ovarian tumor analysis group and more recently the American College of Radiology Ovarian - Adnexal Reporting and Data System Committee have published standardized lexicon for ovarian lesions and encourage ultrasound imagers to adopt this standardized terminology. The aim is to apply the lexicon for risk stratification to allow for consistent follow-up and management. Various methodologies have been tested for characterization of adnexal tumors and to assess risk of malignancy preoperatively. Risk assessment models have been studied against the gold standard of a pattern recognition approach and subjective assessment by an experienced imager. The morphologic patterns of ovarian tumors are detailed and features that are more discriminatory than others in suggesting an ovarian malignancy are described. The imaging pathologic correlation for different tumor types is presented. A brief summary of the ovarian cancer pathologic types and staging of cancer is presented. Finally, the current role of transvaginal sonography as a screening modality for ovarian cancer is discussed. Recently published data show encouraging results, that a multimodal approach of screening for ovarian cancer using transvaginal sonography in women with an elevated CA-125 may prove beneficial and cost effective.