Ultrasonographic ovarian mass scoring system for predicting malignancy in pregnant women with ovarian mass

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.

Struma Ovarii during Pregnancy

Struma ovarii is a rare type of ovarian teratoma primarily composed of over 50% thyroid tissue. Its occurrence is reported in 2-5% of all ovarian teratomas, with approximately 0.5% to 10% showing malignant transformation. Managing it during pregnancy poses significant challenges as pregnancy can promote the growth of malignant struma ovarii due to elevated levels of ovarian and pregnancy-related hormones, including estrogen, progesterone, and human chorionic gonadotrophin (hCG). Most ovarian tumors, including struma ovarii, are detected during routine ultrasonography in the first and second trimesters, often as acute emergencies. Diagnosis during pregnancy is rare, with some cases incidentally discovered during cesarean section when inspecting the adnexa for ovarian cysts. This review explores the diagnostic, management, and therapeutic approaches to struma ovarii during pregnancy.

Validity of ultrasound with color Doppler to differentiate between benign and malignant ovarian tumours

OBJECTIVE

To assess the utility of ultrasound and color Doppler and the Accuracy of International Ovarian Tumor Analysis (IOTA) group classification in the preoperative evaluation of ovarian neoplasms to assess benign or malignant histopathology in the diagnosis of ovarian tumors.

METHODS

This observational longitudinal prospective analysis of 60 patients was performed over a period of 2 years (2017- 2019). The mean age of the patients was 43.75 years. Ultrasonography of ovarian masses were evaluated, and cancer antigen-125 (CA-125) levels were evaluated. Based on the IOTA classification, the B and M features of adnexal masses were studied. Color Doppler imaging was performed to evaluate the patterns of vascularity and indices.

RESULTS

Sixty patients with 35 benign, 23 malignant, and two borderline lesions were included in the study. In malignant lesions, 17 women (73.9%) were above the age of 45. The CA-125 cut off was ≥35 internatioal units/mL. Based on the IOTA classification, 27/35 (77.1%) benign cases, were correctly identified as benign, 6/35 (17.1%) benign cases were incorrectly identified as malignant, and two (5.7%) were found to be inconclusive. In the malignant group, 17 of the 23 patients were identified as having malignancy. Color Doppler showed three (18.8%) benign tumors had a pulsatality index (PI) of <0.8 and 21 malignant tumors had a PI of <0.8. Four benign tumors had an resistive index (RI) of <0.6 and 100% of malignant tumors had an RI <0.6.

CONCLUSION

The IOTA classification is a reliable scoring system for adnexal masses, and color Doppler can help to minimize interobserver variation.

Prediction of the Risk of Malignancy of Adnexal Masses during Pregnancy Comparing Subjective Assessment and Non-Contrast MRI Score (NCMS) in Radiologists with Different Expertise

Ovarian cancer represents 7% of all cancers in pregnant women. Characterising an ovarian mass during pregnancy is essential to avoid unnecessary treatment and, if treatment is required, to plan it accordingly. Although ultrasonography (US) is the first-line modality to characterise adnexal masses, MRI is indicated when adnexal masses are indeterminate at the US examination. An MRI risk stratification system has been proposed to assign a malignancy probability based on the adnexal lesion's MRI, but features of the scoring system require the administration of intravenous gadolinium-based contrast agents, a method that might have a limited use in pregnant women. The non-contrast MRI score (NCMS) has been used and evaluated in non-pregnant women to characterise adnexal masses indeterminate at the US examination. Therefore, we evaluated the diagnostic accuracy of the NCMS in pregnant women, analysing 20 cases referred to our specialised institution. We also evaluated the diagnostic agreement between two radiologists with different expertise. The two readers classified ovarian masses as benign or malignant using both subjective assessment (SA), based on the interpretive evaluation of imaging findings derived from personal experience, and the NCMS, which includes five categories where 4 and 5 indicate a high probability of a malignant mass. The expert radiologist correctly classified 90% of the diagnoses, using both SA and the NCMS, relying on a sensitivity of 85.7% and a specificity of 92.3%, with a false positive rate of 7.7% and a false negative rate of 14.3%. The non-expert radiologist correctly identified patients at a lower rate, especially using the SA. The analysis of the inter-observer agreement showed a K = 0.47 (95% CI: 0.48-0.94) for the SA (agreement in 71.4% of cases) and a K = 0.8 (95% CI: 0.77-1.00) for the NCMS (agreement in 90% of cases). Although in pregnant patients, non-contrast MRI is used, our results support the use of a quantitative score, i.e., the NCMS, as an accurate tool. This procedure may help less experienced radiologists to reduce the rate of false negatives or positives, especially in centres not specialised in gynaecological imaging, making the MRI interpretation easier and more accurate for radiologists who are not experts in the field, either.

Ovarian cancer during pregnancy

Adnexal masses during pregnancy are a relatively uncommon entity. Their clinical management is challenging given the overlapping features of certain entities on imaging and histopathology, which can mimic malignancy, and the potential side effects to the mother and fetus, whether expectant management versus surgery is pursued. Ultrasonography with Doppler evaluation is the modality of choice for evaluating adnexal masses during pregnancy. Magnetic resonance imaging is the second-line modality useful when US findings are inconclusive/indeterminate. Most adnexal masses in pregnant patients are benign in origin (e.g., functional cysts, mature cystic teratoma, decidualization of endometrioma), but a few are malignant in origin (e.g., dysgerminoma, granulosa cell tumor). Most cases of adnexal masses are asymptomatic, but complications such as ovarian torsion can occur. This review aims to familiarize the radiologist with the imaging of adnexal lesions during pregnancy so that the radiologist can identify ovarian cancer. Specifically, the review will detail the most common benign and malignant adnexal masses in pregnancy, mimickers, and their corresponding imaging findings on US and MRI.

Adnexal masses during pregnancy: diagnosis, treatment, and prognosis

Adnexal masses are identified in pregnant patients at a rate of 2 to 20 in 1000, approximately 2 to 20 times more frequently than in the age-matched general population. The most common types of adnexal masses in pregnancy requiring surgical management are dermoid cysts (32%), endometriomas (15%), functional cysts (12%), serous cystadenomas (11%), and mucinous cystadenomas (8%). Approximately 2% of adnexal masses in pregnancy are malignant. Although most adnexal masses in pregnancy can be safely observed and approximately 70% spontaneously resolve, a minority of cases warrant surgical intervention because of symptoms, risk of torsion, or suspicion of malignancy. Ultrasound is the mainstay of evaluation of adnexal masses in pregnancy because of accuracy, safety, and availability. Several ultrasound mass scoring systems, including the Sassone, Lerner, International Ovarian Tumor Analysis Simple Rules, and International Ovarian Tumor Analysis Assessment of Different NEoplasias in the adneXa scoring systems have been validated specifically in pregnant populations. Decisions regarding expectant vs surgical management of adnexal masses in pregnancy must balance the risks of torsion or malignancy with the likelihood of spontaneous resolution and the risks of surgery. Laparoscopic surgery is preferred over open surgery when possible because of consistently demonstrated shorter hospital length of stay and less postoperative pain and some data demonstrating shorter operative time, lower blood loss, and lower risks of fetal loss, preterm birth, and low birthweight. The best practices for laparoscopic surgery during pregnancy include left lateral decubitus positioning after the first trimester of pregnancy, port placement with respect to uterine size and pathology location, insufflation pressure of less than 12 to 15 mm Hg, intraoperative maternal capnography, pre- and postoperative fetal heart rate and contraction monitoring, and appropriate mechanical and chemical thromboprophylaxes. Although planning surgery for the second trimester of pregnancy generally affords time for mass resolution while optimizing visualization with regards to uterine size and pathology location, necessary surgery should not be delayed because of gestational age. When performed at a facility with appropriate obstetrical, anesthetic, and neonatal support, adnexal surgery in pregnancy generally results in excellent outcomes for pregnant patients and fetuses.

Role of Ultrasound in the Assessment and Differential Diagnosis of Pelvic Pain in Pregnancy

Pelvic pain (PP) is common in pregnant women and can be caused by several diseases, including obstetrics, gynaecological, gastrointestinal, genitourinary, and vascular disorders. Timely and accurate diagnosis as well as prompt treatment are crucial for the well-being of the mother and foetus. However, these are very challenging. It should be considered that the physiological changes occurring during pregnancy may confuse the diagnosis. In this setting, ultrasound (US) represents the first-line imaging technique since it is readily and widely available and does not use ionizing radiations. In some cases, US may be conclusive for the diagnosis (e.g., if it detects no foetal cardiac activity in suspected spontaneous abortion; if it shows an extrauterine gestational sac in suspected ectopic pregnancy; or if it reveals a dilated, aperistaltic, and blind-ending tubular structure arising from the cecum in suspicious of acute appendicitis). Magnetic resonance imaging (MRI), overcoming some limits of US, represents the second-line imaging technique when an US is negative or inconclusive, to detect the cause of bowel obstruction, or to characterize adnexal masses.