Interreader Agreement and Intermodality Concordance of O-RADS US and MRI for Assessing Large, Complex Ovarian-Adnexal Cysts.

Purpose To assess interreader agreement of the Ovarian-Adnexal Reporting and Data System (O-RADS) and intermodality concordance between US and MRI for characterizing complex adnexal cysts measuring 5 cm or larger. Materials and Methods This retrospective study included 58 "complex cysts" measuring at least 5 cm in size observed at both US and MRI in 54 women (median age, 37 years ± 12 [SD]; seven postmenopausal women) between July 2017 and June 2020, identified from an electronic US database. A separate set of two blinded radiologists independently reviewed the US or MR images to assign the O-RADS category, and an adjudicator resolved discrepancies (a total of six readers). Lesion outcome (49 benign, eight malignant, one lost to follow-up) was recorded. Interreader agreement of O-RADS US and O-RADS MRI and concordance between US and MRI were analyzed. Results Interreader agreement was fair for US (κ = 0.31), moderate for MRI (κ = 0.43), and moderate between US and MRI (κ = 0.58). A significant positive correlation was found between O-RADS US and MRI (τ = 0.72, P < .001). The O-RADS 4 threshold yielded the highest accuracy for both US and MRI (area under the receiver operating characteristic curve = 0.92 and 0.995, respectively). Considering O-RADS US 4 or 5 as potentially malignant and 1-3 as benign, eight lesions that were assessed as potentially malignant at US were correctly downgraded to benign by using findings at MRI. Using findings at MRI, one malignant lesion that was assessed as benign at US was upgraded to potentially malignant. Conclusion O-RADS US and MRI had excellent performance and positive correlation, but significant interobserver variability remains. Keywords: Ovary, MR Imaging, Ultrasonography © RSNA, 2022 See also the commentary by Baumgarten in this issue.

O-RADS Ultrasound Version 1: A Scenario-Based Review of Implementation Challenges.

The Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound (US) risk stratification and management system was first published by the American College of Radiology in 2020. It provides standardized terminology for evaluation of ovarian and adnexal masses, aids risk stratification, and provides management guidelines for different categories of lesions. This system has been validated by subsequent research and found to be a useful diagnostic and management tool. However, as noted in the system's governing concepts, in some clinical scenarios, such as patients with acute symptoms or with a history of ovarian malignancy, O-RADS US does not apply, or the system's standard management may be adjusted. Additional scenarios, such as an adnexal mass in pregnancy, present challenges in the application of O-RADS US to assist diagnosis and management. The purpose of this article is to highlight 10 clinical scenarios in which O-RADS US version 1 may not apply, may be difficult to apply, or may require modified management. Additional scenarios in which O-RADS US can be appropriately applied are also described.

Thyroid Nodule Shape Independently Predicts Risk of Malignancy.

CONTEXT: Predictive models of thyroid nodule cancer risk are presently based upon nodule composition, echogenicity, margins, and the presence of microcalcifications. Nodule shape has shown promise to be an additive factor helping determine the need for nodule biopsy. OBJECTIVE: We sought to determine if calculation of a nodule's spherical shape independently associates with cancer risk. METHODS: This prospective cohort study, conducted at a single large academic healthcare system in the United States, included patients with 1 or 2 clinically relevant thyroid nodules (predominantly solid and over 1 cm) presenting for diagnostic evaluation. Thyroid ultrasound, cytological evaluation with fine-needle biopsy, and/or histopathological examination on occasion of thyroid surgery were performed. We calculated the nodule's long to short ratio (spherical shape), and its association with tissue proven benign or malignant endpoints. RESULTS: The long to short nodule ratio was significantly lower in malignant compared to benign nodules indicating greater risk of malignancy in more spherical nodules (1.63 ±â€…0.38 for malignant nodules vs 1.74 ±â€…0.47 for benign, P < 0.0001). The risk of malignancy continually increased as the long to short ratio approached a purely spherical ratio of 1.0 (ratio > 2.00, 14.6% cancer; ratio 1.51-2.00, 19.7%; ratio 1.00-1.50, 25.5%, P < 0.0001). In multiple regression analysis, younger age, male sex, and nodule's spherical shape were each independently associated with cancer risk. CONCLUSION: The more a thyroid nodule is spherically shaped, as indicated by a long to short ratio approaching 1.0, the greater its risk of malignancy. This was independent of age, sex, and nodule size. Incorporating a nodule's sphericity in the risk stratification systems may improve individualized clinical decision making.

Role of Sonographic Characteristics of Thyroid Bed Lesions Identified Following Thyroidectomy in the Diagnosis or Exclusion of Recurrent Cancer.

Background US of the thyroid bed in patients with thyroid cancer often depicts small lesions, but it is unclear whether US characteristics of lesions can help predict cancer recurrence. Purpose To determine whether size or US features of lesions in the thyroid bed after thyroidectomy in conjunction with clinical features can help predict thyroid cancer recurrence. Materials and Methods With use of a US reporting database, all patients imaged between July 2006 and June 2016 with an indication of post-thyroidectomy follow-up were retrospectively identified. Recorded data included patient demographic characteristics; date of thyroidectomy; thyroid cancer type; presence, size, and US characteristics of thyroid bed lesions; and results of fine-needle aspiration (FNA). Images were reviewed for lesions that underwent FNA. The Fisher exact test was used for analysis. Results A total of 1885 patients (mean age ± standard deviation, 48 years ± 15; 1493 female patients) underwent 5732 US examinations. Most patients (1541 of 1885 [82%]) had papillary cancer. Overall, 3163 thyroid bed lesions were reported in 5732 US examinations (40.4%). More than half of these lesions (1860 of 3163 [58.8%]) had a maximum measurement of 6 mm or greater. FNA was performed in 144 of the 3163 lesions (4.6%), of which 61 (42.4%) were malignant, 33 (22.9%) were benign, and 50 (34.7%) were nondiagnostic. Five nondiagnostic lesions eventually proved malignant. Only the presence of punctate echogenicities in the lesion (28 of 61 malignant lesions [45.9%]; three of 33 benign lesions [9%]; 12 of 50 nondiagnostic lesions [24%]; P < .001) or the history of positive lymph nodes at thyroidectomy (44 of 61 malignant lesions [72.1%]; 10 of 33 benign lesions [30%]; 19 of 50 nondiagnostic lesions [38%]; P < .001) were associated with malignancy. Of 3019 thyroid bed lesions that did not undergo FNA, three were malignant and 2248 showed no growth at follow-up US ranging from 6 months to 10 years and are presumed benign. Of the 1303 lesions smaller than 6 mm, only two (0.2%) were malignant. Conclusion Small lesions are commonly found in the thyroid bed after thyroidectomy, and most are likely to be benign. Lesions smaller than 6 mm with no punctate echogenicities had a minimal risk for malignancy. © RSNA, 2021 See also the editorial by Grant and Malhi in this issue.

Predictors of Bilateral Disease in Pediatric Differentiated Thyroid Cancer.

CONTEXT: Total thyroidectomy is recommended for children with papillary thyroid carcinoma, partly because of a high prevalence of bilateral disease. Identifying characteristics that predict bilateral disease might identify candidates for more limited surgery. OBJECTIVE: Investigate associations of preoperative or histopathological characteristics with bilateral disease in children with differentiated thyroid cancer. METHODS: Retrospective cohort study (1998-2020) at 2 academic hospitals. Patients <19 years who underwent total thyroidectomy for differentiated thyroid cancer were included. Clinical, sonographic, and histopathological characteristics were evaluated. The presence of bilateral disease on histopathology was assessed by univariable analysis and multivariable logistic regression. RESULTS: One hundred and fifteen subjects were analyzed (90% with papillary carcinoma). Median (range) age at diagnosis was 15.0 (8.1-18.9) years. Bilateral disease was present in 47/115 subjects (41%). Bilateral disease was associated with solid parenchyma, calcifications, irregular margins, and abnormal lymph nodes detected by ultrasound, Bethesda class V/VI cytology, papillary histology, tumor multifocality in the primary lobe, extrathyroidal extension, lymphovascular invasion, and nodal metastases. In multivariable analysis, only multifocality in the primary lobe was independently associated with bilateral disease (OR 7.61, 95% CI 2.44-23.8, P < .001). Among clinically node-negative subjects with papillary carcinoma who did not have tumor multifocality in the primary lobe, bilateral disease was present in 5/32 (16%). CONCLUSIONS: In children with differentiated thyroid cancer, tumor multifocality in the primary lobe is associated with bilateral disease and should prompt consideration of completion thyroidectomy after initial lobectomy. Clinically node-negative children with tumors that are unifocal in the primary lobe have a low likelihood of contralateral disease.

Clinical utility of sonographic features in indeterminate pediatric thyroid nodules.

OBJECTIVE: Surgical resection is recommended for cytologically indeterminate pediatric thyroid nodules due to their intermediate malignancy risk. We evaluated the utility of ultrasound characteristics for refining malignancy risk to inform the management of these nodules. DESIGN: Retrospective cohort study (2004-2019). METHODS: We analyzed consecutive thyroid nodules with indeterminate fine-needle aspiration cytology (Bethesda category III, IV, or V) in pediatric patients (<19 years). We assessed the association of demographic and sonographic characteristics with malignancy risk among all indeterminate nodules and within each Bethesda category. RESULTS: Eighty-seven cytologically indeterminate nodules were identified in 78 patients. Bethesda category was III in 56 nodules (64%), IV in 12 (14%), and V in 19 (22%). The malignancy rate was 46/87 (53%) overall, and 23/56 (41%), 8/12 (75%), and 15/19 (79%) in Bethesda III, IV, and V nodules, respectively. Malignancy rate was higher in solitary nodules (67% vs 37%, P = 0.004) and nodules with irregular margins (100% vs 44%, P < 0.001) or calcifications (82% vs 43%, P = 0.002). American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS) risk level TR5 was associated with a higher rate of malignancy than lower TI-RADS risk levels (80% vs 42%, P = 0.002). Within individual Bethesda categories, TI-RADS risk level was not associated with malignancy. No sonographic feature had a negative predictive value for malignancy greater than 80%. CONCLUSIONS: In pediatric thyroid nodules with indeterminate cytology, some sonographic features - including higher ACR TI-RADS risk level - are associated with malignancy, but these associations are unlikely to alter clinical management in most cases.

Mapping the Ultrasound Landscape to Define Point-of-Care Ultrasound and Diagnostic Ultrasound: A Proposal From the Society of Radiologists in Ultrasound and ACR Commission on Ultrasound.

Current descriptions of ultrasound evaluations, including use of the term "point-of-care ultrasound" (POCUS), are imprecise because they are predicated on distinctions based on the device used to obtain images, the location where the images were obtained, the provider who obtained the images, or the focus of the examination. This is confusing because it does not account for more meaningful distinctions based on the setting, comprehensiveness, and completeness of the evaluation. In this article, the Society of Radiologists in Ultrasound and the members of the American College of Radiology Ultrasound Commission articulate a map of the ultrasound landscape that divides sonographic evaluations into four distinct categories on the basis of setting, comprehensiveness, and completeness. Details of this classification scheme are elaborated, including important clarifications regarding what ensures comprehensiveness and completeness. Practical implications of this framework for future research and reimbursement paradigms are highlighted.

Clinical Significance of Renal Allograft Urothelial Thickening Identified by Ultrasound.

OBJECTIVES: To assess the etiology and clinical implications of ultrasound (US)-diagnosed urothelial thickening (UT) in renal transplants. METHODS: Patients with renal transplants who had UT diagnosed by US from January 2000 to December 2018 were retrospectively identified and compared to patients with transplants without UT scanned during the study period. Medical records were reviewed for demographics, US findings, pathologic results, laboratory values, and clinical outcomes and compared between groups by Fisher exact and t tests. RESULTS: A total of 143 patients with UT and 128 controls comprised our cohorts. The patient age in the UT group versus controls (mean ± SD, 50.2 ± 16.5 versus 51.2 ± 15.3 years) and the time since transplant (2.9 ± 4.2 versus 2.4 ± 5.8 years) were similar. Patients with UT were more likely to be female than controls (76 of 143 [53.1%] versus 53 of 128 [41.4%]; P = .07), but the difference was not statistically significant, and patients with UT were more likely to have indwelling stents (31 of 143 [21.7%] versus 9 of 128 [7.0%]; P = .001) and hydronephrosis (25 of 143 [17.4%] versus 11 of 128 [8.6%]; P = .03). At biopsy, rejection and vascular sclerosis were more likely in patients with UT compared to controls (24 of 25 [49.0%] versus 11 of 43 [25.6%]; P = .031; 42 of 49 [85.7%] versus 22 of 43 [51.2%]; P = .0005, respectively), whereas acute tubular necrosis was similar. The sensitivity (50.0%) and specificity (74.4%) of UT for rejection were low. CONCLUSIONS: Urothelial thickening correlates with US findings of urinary obstruction and indwelling stents, suggesting a possible mechanical component to UT's etiology. Although transplant rejection and vascular sclerosis were more frequent at biopsy in the UT group than controls, UT had low sensitivity and specificity for rejection.

Ultrasound of the Normal Thyroid with Technical Pearls and Pitfalls.

Ultrasound is the best imaging modality for comprehensive evaluation of the thyroid. The thyroid is best imaged using a high-frequency linear probe with the patient in a supine position with the neck hyperextended. Normal thyroid is homogeneous in appearance without defining anatomic landmarks within the gland. A few anatomic variants can occur, and it is important for the sonographer and radiologist to be aware of these variants, to avoid misidentifying them as a pathology. This article provides a comprehensive review of ultrasound of the normal thyroid gland, including technique, normal anatomy, anatomic variants, imaging appearance, and technical pearls and pitfalls.

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.

Assessment of American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) for Pediatric Thyroid Nodules.

Background The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is a recognized tool for management of thyroid nodules in adults but has not been validated in pediatric patients. Purpose To assess the performance of the ACR TI-RADS criteria for guiding decisions on whether to biopsy thyroid nodules in pediatric patients in a single referral center. Materials and Methods In this retrospective study, a database of thyroid nodules in patients younger than 19 years who underwent fine-needle aspiration (FNA) biopsy between January 2004 and July 2017 was analyzed. ACR TI-RADS criteria were applied to each nodule, and an ACR TI-RADS score was created to determine how the nodule would be managed. The number of nodules that would be biopsied with FNA on the basis of ACR TI-RADS was compared with the total number of nodules biopsied with FNA in this clinic to determine if the use of ACR TI-RADS would have changed the rate of FNA (eg, decreased the number of procedures) and whether that change would have affected the timely diagnosis of cancer. Results A total of 314 patients (mean age, 14.9 years; age range, 2-18 years; 28 prepubertal patients; 286 postpubertal patients; 260 female patients) were evaluated. In these 314 patients, 404 thyroid nodules were scored, of which 19.1% (77 of 404) were malignant. Most cancers were papillary carcinoma (68 [88.3%] of 77). The use of ACR TI-RADS criteria for management of nodules in this pediatric study sample would have resulted in 17 (22.1%) of 77 cancers being missed at the patient's initial visit. Conclusion Use of the current American College of Radiology Thyroid Imaging Reporting and Data System criteria for management of pediatric thyroid nodules is inadequate because a high percentage of cancers would be missed at the initial encounter. © RSNA, 2019.

Defining thyroid spherules: A benign cytomorphologic feature that mimics microfollicles.

BACKGROUND: Distinctive rounded structures termed spherules have been observed in thyroid fine-needle aspiration (FNA) samples. Although they are often small and interpreted as microfollicles, spherules are notable for the even spacing of the follicular cells along the perimeter of the structure. Because they have an orderly architectural arrangement, it has been hypothesized that spherules are benign and do not carry the same risk of malignancy that traditional microfollicles do. The aim of this study was to identify the clinical significance and histopathologic correlate of spherules. METHODS: Thyroid FNAs (n = 637) with an interpretation of atypia of undetermined significance (AUS) were reviewed for the presence of spherules, which were defined as small follicles with a rounded, smooth, sharply defined outer contour, evenly spaced nuclei, and a 3-dimensional appearance. Cases were included if spherules accounted for >50% of follicular cell arrangements. Clinical, histopathologic, molecular, and sonographic follow-up data were obtained. RESULTS: Twenty-five spherule cases were identified, and they represented 3.9% of all AUS cases reviewed. All 24 cases with follow-up had a benign outcome. Eleven were tested with the Afirma gene expression classifier; 8 were benign according to the gene expression classifier, and 3 were suspicious but histologically benign after surgical resection. Four additional cases were histologically benign after surgery. Five patients had repeat benign cytology. Four patients had repeat stable ultrasound findings. CONCLUSIONS: Thyroid nodules diagnosed as AUS, if composed predominantly of spherules, are associated with a benign outcome. Recognizing this distinctive cytomorphologic finding may help to reduce the number of FNAs interpreted as AUS and save patients from unnecessary additional testing and surgery.

A Cohort Analysis of Clinical and Ultrasound Variables Predicting Cancer Risk in 20,001 Consecutive Thyroid Nodules.

CONTEXT: Assessing thyroid nodules for malignancy is complex. The impact of patient and nodule factors on cancer evaluation is uncertain. OBJECTIVES: To determine precise estimates of cancer risk associated with clinical and sonographic variables obtained during thyroid nodule assessment. DESIGN: Analysis of consecutive adult patients evaluated with ultrasound-guided fine-needle aspiration for a thyroid nodule ≥1 cm between 1995 and 2017. Demographics, nodule sonographic appearance, and pathologic findings were collected. MAIN OUTCOME MEASURES: Estimated risk for thyroid nodule malignancy for patient and sonographic variables using mixed-effect logistic regression. RESULTS: In 9967 patients [84% women, median age 53 years (range 18 to 95)], thyroid cancer was confirmed in 1974 of 20,001 thyroid nodules (9.9%). Significant ORs for malignancy were demonstrated for patient age <52 years [OR: 1.82, 95% CI (1.63 to 2.05), P < 0.0001], male sex [OR: 1.68 (1.45 to 1.93), P < 0.0001], nodule size [OR: 1.30 (1.14 to 1.49) for 20 to 19 mm, OR: 1.59 (1.34 to 1.88) for 30 to 39 mm, and OR: 1.71 (1.43 to 2.04) for ≥40 mm compared with 10 to 19 mm, P < 0.0001 for all], cystic content [OR: 0.43 (0.37 to 0.50) for 25% to 75% cystic and OR: 0.21 (0.15 to 0.28) for >75% compared with predominantly solid, P < 0.0001 for both], and the presence of additional nodules ≥1 cm [OR: 0.69 (0.60 to 0.79) for two nodules, OR: 0.41 (0.34 to 0.49) for three nodules, and OR: 0.19 (0.16 to 0.22) for greater than or equal to four nodules compared with one nodule, P < 0.0001 for all]. A free online calculator was constructed to provide malignancy-risk estimates based on these variables. CONCLUSIONS: Patient and nodule characteristics enable more precise thyroid nodule risk assessment. These variables are obtained during routine initial thyroid nodule evaluation and provide new insights into individualized thyroid nodule care.

Differences in Thyroid Nodule Cytology and Malignancy Risk Between Children and Adults.

Background: The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) is used to interpret fine-needle aspiration (FNA) cytology of thyroid nodules in children and adults. Nodule management is guided by the implied malignancy risk of each cytological category, which has been derived from adult populations. Whether these implied risks are applicable to pediatric thyroid nodules remains uncertain. We compared malignancy rates between pediatric and adult thyroid nodules within each cytological category. Methods: We evaluated consecutive thyroid nodules ≥1 cm that underwent FNA at the Boston Children's Hospital and Brigham and Women's Hospital from 1998 to 2016. All cytology was interpreted by a single cytopathology group according to the BSRTC. Malignancy rates were compared between pediatric (<19 years) and adult (≥19 years) patients. Results: Four hundred thirty pediatric thyroid nodules and 13,415 adult nodules were analyzed. Pediatric nodules were more likely to be malignant than adult nodules (19% vs. 12%, p = 0.0002). Within cytological categories, malignancy rates were higher in pediatric nodules than in adult nodules that were cytologically nondiagnostic (11% vs. 4%, p = 0.03), atypia of undetermined significance (AUS; 44% vs. 22%, p = 0.004), or suspicious for follicular neoplasm (SFN; 71% vs. 28%, p = 0.001). There were no significant differences between children and adults in the types of thyroid cancers diagnosed in these cytological categories. Among cytologically benign nodules, the difference in malignancy rates was statistically significant but clinically minimal (0.7% vs. 1%, p = 0.001). Malignancy rates did not differ between children and adults among nodules with cytology suspicious for papillary carcinoma (73% vs. 68%, p = 0.67) or positive for malignancy (97% vs. 95%, p = 1). Among the subset of nodules that were resected, the malignancy rate was higher in children than in adults only in nodules that were SFN (71% vs. 36%, p = 0.007). Conclusions: Among thyroid nodules that are cytologically AUS, SFN, or nondiagnostic, malignancy rates are higher in children than in adults. These discrepancies likely represent true differences in malignancy risk between pediatric and adult patients, rather than differences in cytological interpretation. Our findings provide pediatric-specific data to inform the optimal management of thyroid nodules in children, which may differ from that of adult nodules with equivalent cytology.

The Impact of Hashimoto Thyroiditis on Thyroid Nodule Cytology and Risk of Thyroid Cancer.

CONTEXT: The impact of Hashimoto thyroiditis (HT) on the risk of thyroid cancer and its accurate detection remains unclear. The presence of a chronic lymphocytic infiltration imparts a logical mechanism potentially altering neoplastic transformation, while also influencing the accuracy of diagnostic evaluation. METHODS: We performed a prospective, cohort analysis of 9851 consecutive patients with 21,397 nodules ≥1 cm who underwent nodule evaluation between 1995 and 2017. The definition of HT included (i) elevated thyroid peroxidase antibody (TPOAb) level and/or (ii) findings of diffuse heterogeneity on ultrasound, and/or (iii) the finding of diffuse lymphocytic thyroiditis on histopathology. The impact of HT on the distribution of cytology and, ultimately, on malignancy risk was determined. RESULTS: A total of 2651 patients (27%) were diagnosed with HT, and 3895 HT nodules and 10,168 non-HT nodules were biopsied. The prevalence of indeterminate and malignant cytology was higher in the HT vs non-HT group (indeterminate: 26.3% vs 21.8%, respectively, P < 0.001; malignant: 10.0% vs 6.4%, respectively, P < 0.001). Ultimately, the risk of any nodule proving malignant was significantly elevated in the setting of HT (relative risk, 1.6; 95% CI, 1.44 to 1.79; P < 0.001), and was maintained when patients with solitary or multiple nodules were analyzed separately (HT vs non-HT: 24.5% vs 16.3% solitary; 22.1% vs 15.4% multinodular; P < 0.01). CONCLUSION: HT increases the risk of thyroid malignancy in any patient presenting for nodule evaluation. Diffuse sonographic heterogeneity and/or TPOAb positivity should be used for risk assessment at time of evaluation.

Ovarian-Adnexal Reporting Lexicon for Ultrasound: A White Paper of the ACR Ovarian-Adnexal Reporting and Data System Committee.

Ultrasound is the most commonly used imaging technique for the evaluation of ovarian and other adnexal lesions. The interpretation of sonographic findings is variable because of inconsistency in descriptor terminology used among reporting clinicians. The use of vague terms that are inconsistently applied can lead to significant differences in interpretation and subsequent management strategies. A committee was formed under the direction of the ACR initially to create a standardized lexicon for ovarian lesions with the goal of improving the quality and communication of imaging reports between ultrasound examiners and referring clinicians. The ultimate objective will be to apply the lexicon to a risk stratification classification for consistent follow-up and management in clinical practice. This white paper describes the consensus process in the creation of a standardized lexicon for ovarian and adnexal lesions and the resultant lexicon.

Thyroid Nodules in Pediatric Patients: Sonographic Characteristics and Likelihood of Cancer.

Purpose To determine the relationship between demographic and sonographic characteristics of thyroid nodules and malignancy in a pediatric population. Materials and Methods All thyroid nodules in patients younger than 19 years that underwent ultrasound (US)-guided fine-needle aspiration biopsy between January 2004 and July 2017 were retrospectively identified. Age, sex, and background appearance of the thyroid gland were recorded for each patient, and sonographic characteristics and pathologic diagnosis were recorded for each nodule. Demographic and sonographic characteristics were assessed to determine which were associated with malignancy. Categorical and continuous variables and interobserver variability were assessed. Results A total of 404 nodules in 314 patients (82.8% female) (age range, 2-18 years; mean age, 14.9 years) were analyzed. A total of 77 nodules (19.1%) were malignant, the majority of which were papillary thyroid carcinoma (n = 68 [88.3%]). The likelihood of malignancy did not differ between boys and girls (27.8% vs 22.7%, P = .64), nor did it differ between prepubertal and pubertal patients (18.8% vs 19.1%, P > .99). The cancer rate in patients with a solitary nodule was higher than that in patients with multiple nodules (29.4% vs 14.2%, P = .003). Sonographic characteristics associated with malignant nodules included larger size, solid parenchyma, taller-than-wide shape, presence of speckled calcifications, lack of a smooth margin, and presence of abnormal lymph nodes. Interobserver variability for assessment of sonographic characteristics ranged from moderate to very strong. Conclusion In children with thyroid nodules, solitary nodules, larger nodule size, solid parenchyma, taller-than-wide shape, speckled calcifications, irregular margins, and abnormal lymph nodes raise concern for malignancy.

Quantitative Analysis of the Benefits and Risk of Thyroid Nodule Evaluation in Patients ≥70 Years Old.

BACKGROUND: In older patients, thyroid nodules are frequently detected and referred for evaluation, though usually prove to be benign disease or low-risk cancer. Therefore, management should be guided not solely by malignancy risk, but also by the relative risks of any intervention. Unfortunately, few such data are available for patients ≥70 years old. METHODS: All consecutive patients ≥70 years old assessed by ultrasound (US) and fine-needle aspiration (FNA) between 1995 and 2015 were analyzed. Clinical, US, and histologic data, including patient comorbidities and outcomes, were obtained. Imaging and cytology results from initial evaluation were reviewed to detect significant-risk thyroid cancer (SRTC), which was defined as anaplastic, medullary, or poorly differentiated carcinoma, or the presence of distant metastases. Overall survival analyses were then performed to assist with risk-to-benefit assessment. RESULTS: A total of 1129 patients ≥70 years old with 2527 nodules ≥1 cm were evaluated. FNA was safe in all, and cytology proved benign in 67.3% of patients. However, FNA led to surgery in 208 patients, of whom 93 (44.7%) had benign histopathology. Among all patients who underwent FNA, only 17 (1.5%) SRTC were identified, all of which were preoperatively identifiable by imaging and/or cytology. These SRTC were responsible for all (n = 10; 0.9%) thyroid cancer deaths. Among all other patients (n = 1112), 160 deaths (14.4%) were confirmed during a median follow-up of four years. None of these were thyroid cancer related. Survival analysis for these 1112 patients demonstrated that a separate non-thyroidal malignancy or coronary artery disease at the time of nodule evaluation was associated with increased mortality compared to those without these diagnoses (hazard ratio = 2.32 [confidence interval 1.66-3.26]; p < 0.01), confirming these are important variables to identify prior to thyroid nodule evaluation. CONCLUSIONS: For patients ≥70 years old, US and FNA are safe and prove helpful in identifying SRTC and benign cytology. However, the surgical management of patients ≥70 years old presenting without high-risk findings should be tempered, especially when comorbid illness is identified.

Ectopic Intrathyroidal Thymic Tissue Mimicking Thyroid Nodules in Children.

Ectopic intrathyroidal thymic tissue is a benign lesion of nonthyroid origin occasionally found in the pediatric thyroid gland. Accurate diagnosis of such lesions is critical to avoid unnecessary biopsy or surgery. Twelve children referred to our center for the concern of thyroid nodules were found to have intrathyroidal thymic tissue. Most of the lesions had a classic sonographic appearance of a hypoechoic mass with sharp margins and multiple focal internal nonshadowing echogenicities identical to thymic tissue. Sonography and, in select cases, fine-needle aspiration can be used to diagnose benign thymic tissue within the thyroid and avoid unnecessary surgery.

Differential Growth Rates of Benign vs. Malignant Thyroid Nodules.

Context: Thyroid nodule growth was once considered concerning for malignancy, but data showing that benign nodules grow questioned the use of this paradigm. To date, however, no studies have adequately evaluated whether growth rates differ in malignant vs. benign nodules. Objective: To sonographically evaluate growth rates in benign and malignant thyroid nodules ≥1 cm. Design: Prospective, cohort study of patients with tissue diagnosis of benign or malignant disease, with repeated ultrasound evaluation six or more months apart. Main Outcomes: Growth rate in largest dimension of malignant compared with benign thyroid nodules. Regression models were used to evaluate predictors of growth. Results: Malignant nodules (126) met inclusion criteria (≥6-month nonoperative followup) and were compared with 1363 benign nodules. Malignant nodules were not found to be uniquely selected or prospectively observed solely for low-risk phenotype. Median ultrasound intervals were similar (21.8 months for benign nodules; 20.9 months for malignant nodules). Malignant nodules were more likely to grow >2 mm/y compared with benign nodules [relative risk (RR) = 2.5, 95% confidence interval (CI), 1.6 to 3.1; P < 0.001], which remained true after adjustment for clinical factors. The RR of a nodule being malignant increased with faster growth rates. Malignant nodules growing >2 mm/y had greater odds of being more aggressive cancers [intermediate risk: odds ratio (OR) = 2.99; 95% CI, 1.20 to 7.47; P = 0.03; higher risk: OR = 8.69; 95% CI, 1.78 to 42.34; P = 0.02]. Conclusions: Malignant nodules, especially higher-risk phenotypes, grow faster than benign nodules. As growth >2 mm/y predicts malignant compared with benign disease, this clinical parameter can contribute to the assessment of thyroid cancer risk.