O-RADS MRI scoring system has the potential to reduce the frequency of avoidable adnexal surgery

OBJECTIVE

To assess the potential impact of the O-RADS MRI score on the decision-making process for the management of adnexal masses.

METHODS

EURAD database (prospective, European observational, multicenter study) was queried to identify asymptomatic women without history of infertility included between March 1st and March 31st 2018, with available surgical pathology or clinical findings at 2-year clinical follow-up. Blinded to final diagnosis, we stratified patients into five categories according to the O-RADS MRI score (absent i.e. non adnexal, benign, probably benign, indeterminate, probably malignant). Prospective management was compared to theoretical management according to the score established as following: those with presumed benign masses (scored O-RADS MRI 2 or 3) (follow-up recommended) and those with presumed malignant masses (scored O-RADS MRI 4 or 5) (surgery recommended).

RESULTS

The accuracy of the score for assessing the origin of the mass was of 97.2 % (564/580, CI95% 0.96-0.98) and was of 92.0 % (484/526) for categorizing lesions with a negative predictive value of 98.1 % (415/423, CI95% 0.96-0.99). Theoretical management using the score would have spared surgery in 229 patients (87.1 %, 229/263) with benign lesions and malignancy would have been missed in 6 borderline and 2 invasive cases. In patients with a presumed benign mass using O-RADS MRI score, recommending surgery for lesions >= 100 mm would miss only 4/77 (4.8 %) malignant adnexal tumors instead of 8 (50 % decrease).

CONCLUSION

The use of O-RADS MRI scoring system could drastically reduce the number of asymptomatic patients undergoing avoidable surgery.

O-RADS MRI to classify adnexal tumors: from clinical problem to daily use

Eighteen to 35% of adnexal masses remain non-classified following ultrasonography, leading to unnecessary surgeries and inappropriate management. This finding led to the conclusion that ultrasonography was insufficient to accurately assess adnexal masses and that a standardized MRI criteria could improve these patients' management. The aim of this work is to present the different steps from the identification of the clinical issue to the daily use of a score and its inclusion in the latest international guidelines. The different steps were the following: (1) preliminary work to formalize the issue, (2) physiopathological analysis and finding dynamic parameters relevant to increase MRI performances, (3) construction and internal validation of a score to predict the nature of the lesion, (4) external multicentric validation (the EURAD study) of the score named O-RADS MRI, and (5) communication and education work to spread its use and inclusion in guidelines. Future steps will include studies at patients' levels and a cost-efficiency analysis. Critical relevance statement We present translating radiological research into a clinical application based on a step-by-step structured and systematic approach methodology to validate MR imaging for the characterization of adnexal mass with the ultimate step of incorporation in the latest worldwide guidelines of the O-RADS MRI reporting system that allows to distinguish benign from malignant ovarian masses with a sensitivity and specificity higher than 90%. Key points • The initial diagnostic test accuracy studies show the limitation of a preoperative assessment of adnexal masses using solely ultrasonography.• The technical developments (DCE/DWI) were investigated with the value of dynamic MRI to accurately predict the nature of benign or malignant lesions to improve management.• The first developing score named ADNEX MR Score was constructed using multiple easily assessed criteria on MRI to classify indeterminate adnexal lesions following ultrasonography.• The multicentric adnexal study externally validated the score creating the O-RADS MR score and leading to its inclusion for daily use in international guidelines.

Adnexal Lesion Imaging: Past, Present, and Future

Currently, imaging is part of the standard of care for patients with adnexal lesions prior to definitive management. Imaging can identify a physiologic finding or classic benign lesion that can be followed up conservatively. When one of these entities is not present, imaging is used to determine the probability of ovarian cancer prior to surgical consultation. Since the inclusion of imaging in the evaluation of adnexal lesions in the 1970s, the rate of surgery for benign lesions has decreased. More recently, data-driven Ovarian-Adnexal Reporting and Data System (O-RADS) scoring systems for US and MRI with standardized lexicons have been developed to allow for assignment of a cancer risk score, with the goal of further decreasing unnecessary interventions while expediting the care of patients with ovarian cancer. US is used as the initial modality for the assessment of adnexal lesions, while MRI is used when there is a clinical need for increased specificity and positive predictive value for the diagnosis of cancer. This article will review how the treatment of adnexal lesions has changed due to imaging over the decades; the current data supporting the use of US, CT, and MRI to determine the likelihood of cancer; and future directions of adnexal imaging for the early detection of ovarian cancer.

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.

Ovarian Cystadenomas: Growth Rate and Reliability of Imaging Measurements

OBJECTIVES

To evaluate the growth rate of benign ovarian cystadenomas and the degree of variability in ultrasound measurements.

METHODS

Two independent retrospective cohorts of women found to have benign cystadenomas at surgery were identified. To assess growth rate, ultrasounds on women in a community-based health system were reviewed and the growth rate was determined based on the maximum reported size dimension using a mixed effect model. To assess measurement variability, two radiologists independently measured presurgical adnexal imaging findings for women in a tertiary care referral setting. Interobserver, intra-observer, and intermodality (cine clip versus still images) variability in measurements was determined using correlation coefficients (CC) and Bland-Altman analysis, with the proportion of measurements varying by more than 1 cm calculated.

RESULTS

For growth rate assessment, 405 women with 1412 ultrasound examinations were identified. The median growth rate was 0.65 cm/year with mucinous cystadenomas growing faster at 0.83 cm/year compared to 0.51 cm/year for serous cystadenomas (median test P < .0001). To evaluate measurement variability, 75 women were identified with 176 ultrasound studies. The within-subject standard deviations for ultrasound measurements were 0.74 cm for cine clip images and 0.41 cm for static images, with 11% of measurements overall differing by more than 1 cm.

CONCLUSIONS

Cystadenomas grow on average 0.65 cm/year, which is similar in magnitude to the inherent error observed in measurement on ultrasound, suggesting that repeat ultrasound at intervals of longer than a year will often be needed to accurately assess growth if a cyst represents a benign cystadenoma.

Perioperative Nursing Management of Patients Undergoing Laparoscopic Ovarian Cystectomy Guided by Ultrasound Imaging under Intelligent Algorithm

This study was aimed at exploring the application value of ultrasonic imaging-guided laparoscopic ovarian cystectomy after denoising by intelligent algorithms in perioperative nursing intervention of patients. In this study, convolutional downsampling was introduced to the UNet model, based on which the residual structure and Recon module were added to improve the UNet denoising model, which was applied to 100 patients who underwent ultrasound imaging-guided laparoscopic ovarian cystectomy. The patients were grouped into a control group receiving conventional nursing and an experimental group receiving perioperative nursing management. The various experimental indicators were comprehensively evaluated. The results revealed that after denoising using the improved UNet model, the ultrasound image showed no unnecessary interference noise, and the image clarity was significantly improved. In the experimental group, the operation time was 55.45 ± 6.13 days, the intraoperative blood loss was 71.52 ± 9.87 days, the postoperative exhaust time was 1.9 ± 0.73 days, the time to get out of bed was 1.2 ± 0.85 days, the complication rate was 8%, the hospitalization time was 7.3 ± 2.6 days, and the nursing satisfaction rate reached 98%. All above aspects were significantly better than those of the control group, and the differences were statistically significant (P < 0.05). In short, the improved UNet denoising model can effectively eliminate the interference noise in ultrasound and restore high-quality ultrasound images. Perioperative nursing intervention can accelerate the recovery speed of patients, reduce the complication rate, and shorten the length of stay in hospital. Therefore, it was worthy of being widely used in clinical nursing.

Impact of Multiparametric MRI (mMRI) on the Therapeutic Management of Adnexal Masses Detected with Transvaginal Ultrasound (TVUS): An Interdisciplinary Management Approach

RATIONALE AND OBJECTIVES

Adnexal masses detected incidentally at transvaginal ultrasound (TVUS) are a common and still challenging diagnostic problem. The primary goal of further imaging is an accurate tissue characterization so an optimal treatment plan can be devised including surgery only for lesions that are indeterminate or malignant. The aim of this prospective study was to evaluate the diagnostic utility of complementary multiparametric magnetic resonance imaging (mMRI) for treatment planning in patients with adnexal masses, and to assess how it ultimately correlates with subsequent histopathologic findings.

MATERIAL AND METHODS

A total of 126 women (mean age: 54.6 years) with indeterminate adnexal masses underwent mMRI at 3T in addition to TVUS and testing to determine their CA-125 levels. The mMRI protocol consisted of a high-resolution T2-TSE in three planes, diffusion weighted images and dynamic contrast enhanced. First the character of the adnexal mass and the associated management decision (follow-up, laparoscopy or laparotomy) were assessed independently for each diagnostic method (TVUS + CA-125 and mMRI). All methods were then assessed in synopsis. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each diagnostic method alone and in combination were calculated. The standard of reference was either final histology in women who underwent surgery or follow-up of at least 24 months in women who underwent follow-up.

RESULTS

In 67.5% (85/126) of all patients, the adnexal mass was benign; a malignant tumor was diagnosed in 28.6% (36/126) and a borderline tumor in the remaining 4% (5/126) of patients. The diagnostic indices were as follows for TVUS + CA 125 alone, mMRI alone and all three methods combined: sensitivity 86% (31/36), 97% (35/36), and 100% (36/36); specificity 32% (29/90), 83% (75/90), and 80% (68/90); PPV 34% (31/91), 70% (35/50), and 74% (40/54); and NPV 65% (29/44), 98% (75/76), and 100% (72/72). Complementary use of mMRI changed the therapeutic management decision in 34% (41/126) of all patients. In 40.7% (37/91) of patients for whom surgery had been recommended based on TVUS + CA-125, MRI revealed a typical benign finding such that those patients underwent follow-up instead of surgery. None of the examined masses exhibited (tumor) progression or malignancy during the follow-up period. A laparotomy was performed instead of a laparoscopy in 8.7% (11/126) based on the mMRI result.

CONCLUSION

MRI helps significantly improve sensitivity and specificity of diagnosis in patients with indeterminate adnexal masses detected at TVUS. Its diagnostic information revised the planned treatment in more than one-third of women.

The efficiency of susceptibility-weighted MRI in the differentiation of endometriomas from haemorrhagic ovarian cysts

OBJECTIVES

The aim of the study was to investigate the efficiency of susceptibility-weighted magnetic resonance (MR) imaging (SWIs) in differentiating endometriomas from haemorrhagic ovarian cysts.

MATERIALS AND METHODS

Between July 2017 and January 2019, 89 ovarian cystic lesions (57 endometriomas and 32 haemorrhagic cysts) that were identified as complicated cystic lesions on ultrasonography (US) and underwent lower abdominal MRI with susceptibility weighting were retrospectively evaluated. Final diagnoses were obtained with surgical pathological correlation and radiological-clinical follow-up. Two radiologists blinded to the final diagnoses retrospectively reviewed the images in consensus. The signal intensity on T1- and T2-weighted images and curved linear or punctate signal void areas on SWI were noted for the presence of lesions.

RESULTS

Forty of the 57 endometriomas demonstrated the defined MRI criteria, including a cystic hyperintensity on T1-weighted images and hypointensity on T2-weighted images. The remaining 17 lesions did not demonstrate these criteria on conventional MR images. SWI showed punctate or curved linear signal void areas in 53 of 57 endometriomas (92.9%) and none of the haemorrhagic cysts. The sensitivity, specificity and accuracy of SWI in differentiating endometrioma from haemorrhagic cyst were 92.9%, 100.0%, and 95.5%, respectively.

CONCLUSIONS

The addition of the SWI sequence to conventional MRI can help distinguish endometriomas from haemorrhagic ovarian cysts.

Evaluating the added benefit of CT texture analysis on conventional CT analysis to differentiate benign ovarian cysts

PURPOSE

We aimed to evaluate the benefit of adding CT texture analysis on conventional CT features of benign adnexal cystic lesions, especially in identifying mucinous cystadenoma.

METHODS

This retrospective study included patients who underwent surgical removal of benign ovarian cysts (44 mucinous cystadenomas, 32 serous cystadenomas, 16 follicular/simple cysts and 43 endometriotic cysts) at our institution between January 2015 and November 2017. The CT images were independently reviewed by an abdominal radiologist (reviewer 1) and a resident (reviewer 2). Both reviewers recorded the conventional characteristics and performed texture analysis. Based on reviewer 1's results, two decision trees for differential diagnosis were developed. Reviewer 2's results were then applied to the decision trees. The diagnostic performances of each reviewer with and without the decision trees were compared.

RESULTS

Several conventional features and texture analysis parameters showed significant differences between mucinous cystadenomas and other benign adnexal cysts. The first decision tree selected septum number and thickness as significant features, whereas the second decision tree selected septum number and the mean values at spatial scaling factor (SSF) 0. Reviewer 1's performance did not change significantly with or without the use of the decision trees. Reviewer 2's interpretations were significantly less sensitive than reviewer 1's interpretations (p = 0.001). However, when aided by the first and second decision trees, Reviewer 2's interpretations were significantly more sensitive than reviewer 1's interpretations (86.4%, p < 0.001; 72.7%, p = 0.001).

CONCLUSION

This study suggests the benefit of CT texture analysis on conventional images to differentiate mucinous cystadenoma from other benign adnexal cysts, particularly for less experienced radiologists.

Decoding incidental ovarian lesions: use of texture analysis and machine learning for characterization and detection of malignancy

PURPOSE

To compare CT texture features of benign and malignant ovarian lesions and to build a machine learning model to detect malignancy in incidental ovarian lesions.

METHODS

In this IRB-approved, HIPAA-compliant, retrospective study, 427 consecutive patients with incidental ovarian lesions detected on contrast-enhanced CT (348, 81.5% benign and 79, 18.5% malignant) were included. The following CT texture features were analyzed using commercially available software (TexRAD, Feedback Plc, Cambridge, UK): total pixel, mean, standard deviation (SD), entropy, mean value of positive pixels (MPP), skewness, kurtosis and entropy. Three machine learning models were created by combining texture features and patients' age, and performance of these models was assessed using tenfold cross-validation. Receiver operating characteristics (ROC) were constructed to assess sensitivity and specificity. The cutoff value was picked using a cost-weighted method.

RESULTS

Total pixels, mean, SD, entropy, MPP, and skewness were significantly different between benign and malignant groups (p < 0.05). With a selected 10 as a cost factor to optimize cutoff value selection, sensitivity 92%, specificity 60% in the random forest (RF) model, sensitivity 91%, specificity 69% in SVM model, and sensitivity 92%, specificity 61% in the logistic regression, respectively.

CONCLUSION

CT texture analysis could provide objective imaging analysis of incidental ovarian lesions and ML models using CT texture features and age demonstrated high sensitivity and moderate specificity for detection of malignant lesions.

ACR Appropriateness Criteria® Postmenopausal Acute Pelvic Pain

Acute pelvic pain is a common presenting complaint in both the emergency room and outpatient settings. Pelvic pain of gynecologic origin in postmenopausal women occurs less frequently than in premenopausal women; however, it has important differences in etiology. The most common causes of postmenopausal pelvic pain from gynecologic origin are ovarian cysts, uterine fibroids, pelvic inflammatory disease, and ovarian neoplasm. Other etiologies of pelvic pain are attributable to urinary, gastrointestinal, and vascular systems. As the optimal imaging modality varies for these etiologies, it is important to narrow the differential diagnosis before choosing the initial diagnostic imaging examination. Transabdominal and transvaginal ultrasound are the best initial imaging techniques when the differential is primarily of gynecologic origin. CT with intravenous (IV) contrast is more useful if the differential diagnosis remains broad. MRI without IV contrast or MRI without and with IV contrast, as well as CT without IV contrast may also be used for certain differential considerations. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Surveillance in Older Women With Incidental Ovarian Cysts: Maximal Projected Benefits by Age and Comorbidity Level

PURPOSE

The aim of this study was to estimate effects on life expectancy (LE) of imaging-based ovarian surveillance after detection of incidental postmenopausal ovarian cysts, under different assumptions of patient age, comorbidity level, and cancer risk and detection.

METHODS

A decision-analytic Markov model was developed to estimate LE benefits. Hypothetical cohorts of postmenopausal women with simple ovarian cysts were evaluated, with varied age (66-80 years) and comorbidity level (none, mild, moderate, severe). For each cohort, imaging "follow-up" (2 years) and "no-follow-up" strategies were compared. Consistent with current evidence, increased cancer risk in patients with cysts was not assumed; however, incident ovarian cancers could be detected during follow-up. To estimate theoretical maximal LE gains from follow-up, perfect ovarian cancer detection and treatment during follow-up were assumed. This and other key assumptions were varied in sensitivity analysis.

RESULTS

Projected LE gains from follow-up were limited. For 66-, 70-, 75-, and 80-year-old women with no comorbidities, LE gains were 5.1, 5.1, 4.5, and 3.7 days; with severe comorbidities, they were 3.5, 3.2, 2.7, and 2.1 days. With sensitivity of 50% for cancer detection, they were 3.7 days for 66-year-old women with no comorbidities and 1.3 days for 80-year-old women with severe comorbidities. When cancer risk for women with cysts was assumed to be elevated (1.1 times average risk), LE gains increased only modestly (5.6 and 2.3 days for analogous cohorts).

CONCLUSIONS

Even in the circumstance of perfect ovarian cancer detection and treatment, surveillance of postmenopausal women (≥66 years of age) with simple cysts affords limited benefits, particularly in women with advanced age and comorbidities.

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.

Risk of endometrial cancer among women with benign ovarian tumors - A Danish nationwide cohort study

OBJECTIVE

The few studies on the association between benign ovarian tumors and endometrial cancer have been inconclusive. Using data from a large Danish register-based cohort study, we assessed the overall and type-specific risk of endometrial cancer among women with a benign ovarian tumor.

METHODS

We identified all Danish women diagnosed with a benign ovarian tumor during 1978-2016 in the Danish National Patient Register (n = 149,807). The study population was followed for subsequent development of endometrial cancer by linkage to the Danish Cancer Register and standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (CIs) were calculated after correction for hysterectomy.

RESULTS

After a one-year delayed study entry, women with benign ovarian tumors had a decreased incidence of endometrial cancer (SIR = 0.74, 95% CI: 0.68-0.81) compared with women in the general Danish population. Both solid benign ovarian tumors (SIR = 0.79, 95% CI 0.70-0.88) and cystic benign ovarian tumors (SIR = 0.68, 95% CI 0.58-0.78) were associated with decreased incidences of endometrial cancer. Likewise, women with benign ovarian tumors had decreased incidences of both type I and type II endometrial cancer. The incidence of endometrial cancer was decreased to virtually the same magnitude irrespective of the age at diagnosis of a benign ovarian tumor and the reduction persisted throughout the follow-up period.

CONCLUSIONS

The risk of endometrial cancer was decreased beyond the first year after a benign ovarian tumor and the decrease persisted for 20 or more years. The possible underlying mechanisms are not known and should be investigated further.

Impact of a Multifaceted Information Technology-Enabled Intervention on the Adoption of ACR White Paper Follow-Up Recommendations for Incidental Adnexal Lesions Detected on CT

OBJECTIVE. The objective of our study was to improve adherence to American College of Radiology (ACR) white paper follow-up imaging recommendations for incidental adnexal lesions seen on pelvic CT (herein referred to as "adherence rate to recommendations"). MATERIALS AND METHODS. This quality improvement project was conducted at a large academic teaching hospital. The baseline adherence rate to recommendations was assessed by screening all pelvic CT reports for the period from October 22, 2016, through December 22, 2016, for incidental adnexal findings, followed by manual review. Forty abdominal and cancer imaging radiologists were surveyed to understand the barriers to adoption of the recommendations. Interventions to address the most common identified barriers were implemented on December 23, 2016. The postintervention adherence rate was assessed from December 23, 2016, through February 15, 2017, by again screening CT pelvis reports for incidental adnexal lesions followed by manual review. The change in pre- and postintervention adherence rates was assessed using the Fisher exact test and statistical process control (SPC) p-chart with 3-sigma control limits. RESULTS. The adherence rate to recommendations at baseline was 67% (121/181). Of the 28 of 40 (70%) radiologists who completed the survey, only 29% (8/28) often or consistently used the recommendations. Not remembering the details of the recommendations or not having time to look them up accounted for 83.3% of the barriers cited by radiologists. Interventions consisted of radiologist education and creation of an easily accessible clinical decision support tool incorporated into radiology reporting workflow. The adherence rate to recommendations after the intervention increased to 87% (129/148; p < 0.0001), as also shown by the SPC chart. CONCLUSION. The rate of adherence to follow-up imaging recommendations significantly increased after radiologist education and incorporation of recommendations into the radiologist workflow.

Adnexal lesions detected on CT in postmenopausal females with non-ovarian malignancy: do simple cysts need follow-up?

PURPOSE

To assess whether CT morphology of adnexal lesions in postmenopausal women with history of non-ovarian cancer could be used to discriminate benign and malignant lesions, particularly focusing on applicability of the ACR criteria.

MATERIALS AND METHODS

This was an IRB-approved HIPAA-compliant retrospective review of contrast-enhanced CTs of 199 women, 55 years and older. Lesions were classified as simple cystic, complex cystic, solid-cystic, or solid based on CT morphology, and were diagnosed as benign, indeterminate, or malignant on follow-up imaging or pathology. Associated metastatic disease was noted, if present. Findings were analyzed to correlate CT morphology, primary tumor pathology, and metastatic disease pattern with eventual lesion diagnosis.

RESULTS

There were 223 adnexal lesions, including 123 (55%) simple cystic, 48 (22%) complex cystic, 40 (18%) solid-cystic, and 12 (5%) solid lesions. 186/223 (83%) lesions were benign, and 37/223 (17%) were malignant. Primary colorectal cancer was significantly associated with an increased likelihood of malignant adnexal lesions (OR 10.2, p < 0.001) compared to patients with other cancers. Adnexal malignancy was significantly associated with the presence of non-ovarian peritoneal metastases (p < 0.001). None of the simple cysts (including 85 cysts between 1-3 cm and 38 cysts > 3 cm) were found to be malignant (malignancy rate: 0.0%, 95% CI 0.0-3.0%). Complex cysts were more likely to be malignant than simple cysts (p = 0.002) and solid-cystic lesions were more likely to be malignant than complex cysts (p < 0.001).

CONCLUSION

Simple adnexal lesions on CT in this cohort were unlikely to be malignant, supporting the ACR guidelines. A higher size threshold of 3 cm (vs. 1 cm) may be preferred in all cases of simple cysts for recommending further follow-up. However, more complex-appearing cysts need further evaluation as the risk of malignancy is increased. Peritoneal metastases have a significant correlation with malignant adnexal involvement.