Molecular classification of follicular thyroid carcinoma based on TERT promoter mutations.

Follicular thyroid carcinoma (FTC) has different clinicopathological characteristics than papillary thyroid carcinoma. However, there are no independent systems to predict cancer-specific survival (CSS) in FTC. Telomerase reverse transcriptase (TERT) promoter mutations are associated with tumor aggressiveness. Thus, it could be a potential prognostic marker. The aim of this study was to refine the CSS risk prediction using TERT promoter mutations in combination with the fourth edition of World Health Organization (WHO 2017) morphological classification. We investigated 77 FTC patients between August 1995 and November 2020. Cox regression was used to calculate hazard ratios to derive alternative groups. Disease-free survival (DFS) and CSS predictability were compared using Proportion of variation explained (PVE) and C-index. CSS was significantly different in encapsulated angioinvasive (EA)-FTC patients stratified by TERT promoter mutations [wild-type (WT-TERT) vs. mutant (M-TERT); P < 0.001] but not in minimally invasive (MI)-FTC and widely invasive (WI)-FTC patients (P = 0.691 and 0.176, respectively). We defined alternative groups as follows: Group 1 (MI-FTC with WT-TERT and M-TERT; EA-FTC with WT-TERT), Group 2 (WI-FTC with WT-TERT), and Group 3 (EA-FTC with M-TERT; WI-FTC with M-TERT). Both PVE (22.44 vs. 9.63, respectively) and C-index (0.831 vs. 0.731, respectively) for CSS were higher in the alternative groups than in the WHO 2017 groups. Likewise, both PVE (27.1 vs. 14.9, respectively) and C-index (0.846 vs. 0.794, respectively) for DFS were also higher in the alternative groups than in the WHO 2017 groups. Alternative group harmonizing of the WHO 2017 classification and TERT promoter mutations is effective in predicting CSS in FTC patients, thereby improving DFS predictability.

Approach to Bethesda system category III thyroid nodules according to US-risk stratification.

This study evaluated how to manage Bethesda category III (Bethesda III) (atypia of undetermined significance/follicular lesion of undetermined significance [AUS/FLUS]) thyroid nodules according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) to reduce unnecessary surgeries. A total of 161 thyroid nodules diagnosed as Bethesda III underwent surgery from 2016 to 2019. Ultrasonography-guided fine-needle aspiration (US-FNA) or core needle biopsy (CNB) was used for repeat examination. K-TIRADS category was assigned to the thyroid nodules. The proportion of malignancy in Bethesda III nodules confirmed by surgery were significantly increased in proportion relative to K-TIRADS with 60.0% low suspicion, 88.2% intermediate suspicion, and 100% high suspicion nodules (p < 0.001). The proportion of malignancy in AUS and FLUS were significantly different (94.2% vs. 40.0% p = 0.003). The proportion of malignancy in AUS increased with K-TIRADS categories, but there was no difference in FLUS. All K-TIRADS high suspicion nodules were AUS as papillary carcinomas (99%), while 80% of FLUS nodules and 50% of follicular carcinomas showed K-TIRADS low suspicion. In 116 nodules with repeat FNA or CNB after initial Bethesda III results, the conclusive result rate was significantly increased in proportion to K-TIRADS with 58.3% low suspicion, 83.3% intermediate suspicion, and 88.8% high suspicion nodules (p = 0.015). K-TIRADS low suspicion nodules of Bethesda III nodules should be managed after risk-benefit consideration rather than immediate surgery or repeat examination. K-TIRADS for Bethesda III nodules can predict papillary carcinoma well, but not follicular carcinoma.

Surgeon Volume and Long-Term Oncologic Outcomes in Patients with Medullary Thyroid Carcinoma.

BACKGROUND: Surgery is the most important curative treatment for medullary thyroid carcinoma (MTC). The relationship between surgeon volume (the number of surgeries performed) and short-term surgical outcomes, such as increased postoperative complication or costs, is well established. This study evaluated whether surgeon volume influenced long-term oncologic outcomes. METHODS: We retrospectively reviewed 246 patients diagnosed with MTC after initial thyroid surgery from 1995 to 2019. After exclusion, 194 patients were eligible for inclusion in the study. Surgeons were categorized as low/intermediate volume (fewer than 100 operations per year) or high volume (at least 100 operations per year). RESULTS: Of the 194 included patients, 60 (30.9%) developed disease recurrence, and 9 (4.6%) died of MTC during the median follow-up of 92.5 months. Having a low/intermediate-volume surgeon was associated with high disease recurrence (log-rank test, p < 0.001). After adjustment for age, sex, tumor type (sporadic versus hereditary), primary tumor size, presence of central lymph node metastasis (LNM), presence of lateral LNM, extrathyroidal extension, and positive resection margin, surgeon volume was a significant factor for disease recurrence (hazard ratio 2.28, p = 0.004); however, cancer-specific survival was not affected by surgeon volume (hazard ratio 4.16, p = 0.115). CONCLUSIONS: Surgeon volume is associated with long-term oncologic outcome. MTC patients will be able to make the best decisions for their treatment based on the results of this study.

Ultrasonographic characteristics of medullary thyroid carcinoma according to nodule size: application of the Korean Thyroid Imaging Reporting and Data System and American Thyroid Association guidelines.

BACKGROUND: Few studies have categorized ultrasound (US) findings of various sized medullary thyroid carcinomas (MTCs) according to updated guidelines. PURPOSE: To evaluate and compare the differences in US findings of MTC according to nodule size, using the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and American Thyroid Association (ATA) guidelines. MATERIAL AND METHODS: The study included 119 patients with 129 MTC nodules, which were surgically confirmed at our institution between March 1999 and September 2017. Nodules were divided into large (≥1.0 cm) and small (<1.0 cm) groups. US images were analyzed according to the K-TIRADS and ATA guidelines. The differences in US characteristics between small and large nodules were compared using Fisher's exact or Chi-square tests. RESULTS: Of 129 MTC nodules, 84 (65.1%) were large nodules and 45 (34.9%) were small nodules. According to the nodule size, small MTC nodules were classified more commonly as high suspicion by K-TIRADS and ATA (95.6% and 93.3%, respectively) (P < 0.001), but presented neither cystic change, isoechogenicity, nor low suspicion category by K-TIRADS and ATA. In contrast, large MTC nodules showed more frequently cystic change (15.5%), isoechogenicity (16.7%), smooth margins (50%), or low or intermediate suspicion US features by K-TIRADS and ATA (59.6% and 36.0%, respectively) (all P values < 0.001). CONCLUSION: Most small MTC nodules are classified as high suspicion on US, whereas large MTC nodules are diagnosed more frequently as low or intermediate suspicion by K-TIRADS and ATA.

Ultrasound-guided fine-needle aspiration or core needle biopsy for diagnosing follicular thyroid carcinoma?

OBJECTIVE: We evaluated the preoperative diagnostic values of ultrasound (US), fine-needle aspiration (FNA) and core needle biopsy (CNB) leading to surgery in patients with FTC. METHODS: From October 1994 to July 2016, 298 patients with FTC who had preoperative US images and underwent US-guided FNA or CNB and surgery were included in this study. We evaluated the results of preoperative FNA or CNB based on the Bethesda system and the US findings according to the Korean thyroid imaging reporting and data system (K-TIRADS). RESULTS: Predominant US features of FTC showed solid, hypo- or iso-echogenicity, oval smooth margin and halo with no calcification. Based on K-TIRADS, 140 (47.0%) patients with FTC were categorized as low suspicion, 133 (44.63%) as intermediate suspicion and 25 (8.4%) as high suspicion at US. Considering only FNA cytology (n = 230), 6.9% were revealed as Bethesda class I, 16.1% as class II, 37.0% as class III, 29.1% as class IV and 10.9% as class V. Considering the 68 cases with CNB results, 2.9% were revealed as class I, 4.4% as class II, 20.6% as class III and 72.1% as class IV. Despite multiple FNAs, 16.7% of the 84 patients with FTC still obtained Bethesda class I or class II. CNB results in patients with FTC had a significantly higher rate of Bethesda class IV compared to the FNA results (P < .001). FTCs with distant metastasis exhibited a significantly higher rate of Bethesda classes IV and V compared to those without distant metastasis (P = .004). CONCLUSION: Surgery for FTC is deferred only with preoperative US and FNA. CNB in patients with FTC can lead to surgery better than FNA. Therefore, if the US feature is characteristic and a serially growing large nodule is suspected, the first attempt of CNB may be helpful in selecting a surgical candidate.

Molecular genotyping of the non-invasive encapsulated follicular variant of papillary thyroid carcinoma.

AIMS: The non-invasive encapsulated follicular variant of papillary thyroid carcinoma (FVPTC) has been managed as a low-risk malignancy. Recently, a proposal was made to reclassify this tumour type as a premalignant lesion and rename it non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This study aims to provide the first comprehensive study on molecular genotype-phenotype correlations of encapsulated FVPTC. METHODS AND RESULTS: This study was performed on 177 consecutive FVPTCs from January 2014 to April 2016. These were classified as non-invasive encapsulated FVPTC (n = 74) invasive encapsulated FVPTC (n = 51), and infiltrative FVPTC (n = 52), according to standard criteria, by two independent pathologists. Genetic alterations and other clinicopathological information were compared. BRAFV600E was found in 12.2% (non-invasive) and 11.8% (invasive) of encapsulated FVPTCs, and in 34.6% of infiltrative FVPTCs (P = 0.001). Mutation in encapsulated FVPTCs was limited to cases with rare or abortive papillae. RET-PTC1 and RET-PTC3 rearrangements were present (11.5%) only in infiltrative FVPTCs. In contrast, NRAS, HRAS and KRAS mutations were observed more often in encapsulated FVPTCs (48.6% in non-invasive and 66.7% in invasive) than in infiltrative FVPTCs (15.4%) (P < 0.001). Preoperative cytological examination did not distinguish between non-invasive and invasive encapsulated FVPTCs, whereas infiltrative FVPTC was more likely to be Bethesda class V/VI than the encapsulated type (60.4% versus 38.1%; P = 0.01). CONCLUSIONS: There were no differences in clinicopathological or molecular profiles between non-invasive and invasive encapsulated FVPTCs, except in vascular and capsular invasion. Therefore, the diagnosis of NIFTP, like that of follicular adenoma, may require surgical resection and exclusion of those tumours with any papillae.

Breast Cancer Heterogeneity: MR Imaging Texture Analysis and Survival Outcomes.

Purpose To determine the relationship between tumor heterogeneity assessed by means of magnetic resonance (MR) imaging texture analysis and survival outcomes in patients with primary breast cancer. Materials and Methods Between January and August 2010, texture analysis of the entire primary breast tumor in 203 patients was performed with T2-weighted and contrast material-enhanced T1-weighted subtraction MR imaging for preoperative staging. Histogram-based uniformity and entropy were calculated. To dichotomize texture parameters for survival analysis, the 10-fold cross-validation method was used to determine cutoff points in the receiver operating characteristic curve analysis. The Cox proportional hazards model and Kaplan-Meier analysis were used to determine the association of texture parameters and morphologic or volumetric information obtained at MR imaging or clinical-pathologic variables with recurrence-free survival (RFS). Results There were 26 events, including 22 recurrences (10 local-regional and 12 distant) and four deaths, with a mean follow-up time of 56.2 months. In multivariate analysis, a higher N stage (RFS hazard ratio, 11.15 [N3 stage]; P = .002, Bonferroni-adjusted α = .0167), triple-negative subtype (RFS hazard ratio, 16.91; P < .001, Bonferroni-adjusted α = .0167), high risk of T1 entropy (less than the cutoff values [mean, 5.057; range, 5.022-5.167], RFS hazard ratio, 4.55; P = .018), and T2 entropy (equal to or higher than the cutoff values [mean, 6.013; range, 6.004-6.035], RFS hazard ratio = 9.84; P = .001) were associated with worse outcomes. Conclusion Patients with breast cancers that appeared more heterogeneous on T2-weighted images (higher entropy) and those that appeared less heterogeneous on contrast-enhanced T1-weighted subtraction images (lower entropy) exhibited poorer RFS. © RSNA, 2016 Online supplemental material is available for this article.

Follicular variant of papillary thyroid carcinoma: comparison of ultrasound-guided core needle biopsy and ultrasound-guided fine needle aspiration in a multicentre study.

OBJECTIVE: Pre-operative diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) by ultrasound-guided fine needle aspiration (US-FNA) remains a challenge. The goal of this study was to investigate whether ultrasound-guided core needle biopsy (US-CNB) is superior to US-FNA in refining the surgical indications for the treatment of FVPTC. DESIGN: This retrospective study enrolled 212 patients with 218 FVPTCs who were surgically confirmed at three university hospitals from January 2008 through December 2014. All patients underwent both or either US-FNA or US-CNB. FNA and CNB results were divided into identified surgical candidates or not based on the Bethesda system. Relevant clinical information and the rate of surgical candidates were compared between US-FNA and US-CNB groups. RESULTS: Among 218 thyroid nodules, US-FNA was performed for 200 nodules and US-CNB for 51 nodules. Thirty-three nodules underwent both US-FNA and US-CNB. The rates of surgical candidates identified by US-FNA and US-CNB were 61·5% and 86·3%, respectively (P = 0·001). The rates of surgical candidates identified by repeat US-FNA and initial US-FNA with subsequent US-CNB were 53·9% and 78·8%, respectively (P = 0·042). A precise diagnosis of FVPTC was made in 1% of the patients in the US-FNA group and in 29·4% of the patients in the US-CNB group. The predominant US findings of FVPTCs included solid tumours (89·4%), wider-than-tall shape (82·6%), no calcifications (51·3%), hypoechogenicity (46·3%) and indeterminate diagnosis on US (50·5%). CONCLUSIONS: In patients with FVPTC, US-CNB is a superior indicator for surgery compared to US-FNA. If a FVPTC is suspected but is initially indeterminate at FNA cytology, subsequent US-CNB should be considered instead of repeat US-FNA.

Preoperative differentiation between noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and non-NIFTP.

BACKGROUND: A recent concept was proposed that the noninvasive encapsulated follicular variant of papillary thyroid carcinoma reclassified as "noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)" is benign. Our aim was to identify the differences between NIFTP and non-NIFTP preoperatively. METHODS: This retrospective study included a total of 208 patients with 208 follicular variant of papillary thyroid carcinomas (FVPTC) that were surgically confirmed at three university hospitals from 2008 to 2014. Clinical factors, the biopsy techniques and ultrasonography (US) imaging characteristics were compared between the NIFTP and non-NIFTP groups. RESULTS: A total of 34 NIFTP (16·3%) and 174 non-NIFTP (83·7%) were observed. For NIFTPs, the need for surgery was indicated by ultrasonography-guided fine needle aspiration (US-FNA) in 54·3% and by ultrasonography-guided core needle biopsy (US-CNB) in 100% (P = 0·008). For non-NIFTP, no significant difference was noted in the rates of surgical indication between US-FNA and US-CNB (62·6% vs 78·9%, P = 0·054). The most common biopsy diagnosis of NIFTP was Bethesda category V (28·6%) in the US-FNA group and category IV (45·5%) in the US-CNB group. US diagnosis of NIFTP had a significantly lower rate of the high suspicion of malignancy than that of non-NIFTP (14·7% vs 37·9%, P = 0·024). Central nodal metastasis was found in only one case (2·9%) of NIFTP patients, but none had distance metastasis or recurrence. CONCLUSION: Noninvasive follicular thyroid neoplasm with papillary-like nuclear features lacks malignant US features and is better triaged using US-CNB than using US-FNA to facilitate the surgical management. US evaluation is pivotal in determining the next step of FVPTC management.

Comparison between two-dimensional synthetic mammography reconstructed from digital breast tomosynthesis and full-field digital mammography for the detection of T1 breast cancer.

OBJECTIVE: To evaluate the interpretative performance of two-dimensional (2D) synthetic mammography (SM) reconstructed from digital breast tomosynthesis (DBT) in the detection of T1-stage invasive breast cancers, compared to 2D full-field digital mammography (FFDM). METHODS: This retrospective study enrolled 214 patients. For each patient, FFDM and DBT were performed between January and June 2013, and SM was reconstructed from DBT data. Three radiologists interpreted images and recorded visibility scores and morphologies of cancers. Diagnostic performances of SM and FFDM were compared. Percentages of detected cancers and visibility scores were compared for tumour size, and presence of calcifications for each observer. RESULTS: Observer sensitivity showed no difference for detection with SM and FFDM (P > 0.05). One observer showed a higher specificity (P = 0.02) and higher positive predictive value with SM (95 % CI 0.6-16.4), but the differences in the corresponding values between SM and FFDM for the other observers were not statistically significant. In subgroup analyses according to tumour size and presence of calcifications, percentages of detected cancers and visibility scores were not significantly different. CONCLUSIONS: Diagnostic performances of SM and FFDM are comparable for detecting T1-stage breast cancers. Therefore, our results indicate that SM may eliminate the need for additional FFDM during DBT-based imaging. KEY POINTS: • DBT plus FFDM increases radiation dose compared to FFDM alone. • Detecting T1-stage cancers with only SM is comparable to detection with FFDM. • Two-dimensional SM may replace dose-requiring FFDM in DBT-based imaging.

Ultrasonographic features and clinical characteristics of Warthin-like variant of papillary thyroid carcinoma.

Warthin-like variant of papillary thyroid carcinoma (WVPTC) is a rare entity recently characterized. We evaluated ultrasonographic (US) features and clinical characteristics of WVPTC. Nine patients were diagnosed with WVPTC through surgery in our institution from May 2005 to January 2015. Eight of nine patients had available preoperative US images. A retrospective review of the US and clinical characteristics was performed. WVPTC compromised of 0.06% of 14,071 PTCs surgically confirmed. A mean age of nine patients was 53.2 years (range, 32-75 years). The mean nodule size of nine WVPTCs was 0.9 cm (range, 0.5-1.5 cm). Two patients showed central nodal metastasis and one patient with conventional PTC as an index tumor underwent central and lateral neck dissection. No one showed recurrence or distant metastasis during the follow-up period (mean, 4.6 years; range, 0.6-10 years). The most common US features of WVPTCs were solid composition (62.5%), hypoechogenicity (75%), and wider-than-tall shape (100%), respectively. Four (50%) of eight nodules showed well-defined margin and three (37.5%) of them had cystic component. One of eight resembled focal thyroiditis. Three nodules were considered as probably benign with US. All nine cases demonstrated underlying heterogeneous parenchymal echogenicity and accompanied chronic lymphocytic thyroiditis in permanent sections. Thyroid function tests in all patients were normal except for one with subclinical hypothyroidism. WVPTC is an uncommon subtype of PTC and has favorable prognosis, which can be misdiagnosed as a probably benign nodule or focal thyroiditis with US. All cases are associated with heterogeneous parenchyma in the background.

Shear-wave elastography in invasive ductal carcinoma: correlation between quantitative maximum elasticity value and detailed pathological findings.

BACKGROUND: Further information is needed regarding whether histopathological characteristics affect breast tumor elasticity. PURPOSE: To determine whether maximum elasticity values vary according to tumor-stroma ratio, dominant stroma type, or presence of fibrosis in invasive breast cancer. MATERIAL AND METHODS: This study included 71 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast shear-wave elastography (SWE). Maximum elasticity (Emax) values were retrospectively correlated with pathological findings that included tumor-stroma ratio, dominant stroma type (collagen, fibroblast, lymphocyte), and fibrosis. Multiple linear regression analysis was performed to determine variables independently associated with Emax. RESULTS: High histologic grade was significantly correlated with higher Emax (P = 0.042). Estrogen receptor and progesterone receptor expression negatively correlated with high elasticity values (P = 0.013 and P = 0.03, respectively). Breast cancers that exhibited higher cellularity demonstrated a greater level of stiffness that was not statistically significant (ρ = 0.153; P = 0.193). While dominant stroma type and fibrosis did not affect Emax (P = 0.197 and P = 0.598, respectively), lesion size was significantly associated with Emax (ρ = 0.474, P < 0.001). On multivariate analysis, only lesion size was significantly associated with Emax (P < 0.001). CONCLUSION: The composition of tumors did not affect their Emax.

Description and Comparison of the Sonographic Characteristics of Poorly Differentiated Thyroid Carcinoma and Anaplastic Thyroid Carcinoma.

OBJECTIVES: Although poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma account for a substantial portion of the morbidity and mortality associated with thyroid cancer, a chance of a cure exists with aggressive treatment, especially in patients with poorly differentiated thyroid carcinoma. The goal of this study was to evaluate the sonographic characteristics of poorly differentiated thyroid carcinoma and to compare the sonographic findings of poorly differentiated and anaplastic thyroid carcinomas. METHODS: The study included 29 patients with 30 poorly differentiated thyroid carcinomas and 26 patients with 26 anaplastic thyroid carcinomas. Two radiologists retrospectively reviewed sonographic findings. Clinical and sonographic findings were compared between poorly differentiated and anaplastic thyroid carcinomas by univariate and multivariate analyses. RESULTS: In the group of patients with poorly differentiated thyroid carcinoma, the mean age was 53.7 years (range, 14-73 years), and the mean tumor size was 3.6 cm (range, 0.6-10.0 cm). The common sonographic findings of poorly differentiated thyroid carcinoma were heterogeneous echogenicity (93.3%), solitary nodules (80.0%), a circumscribed margin (63.3%), an oval-to-round shape (63.3%), and hypoechogenicity (60.0%). A circumscribed margin (P = .003) and an oval-to-round shape (P = .015) were significantly more frequent in poorly differentiated thyroid carcinoma than in anaplastic thyroid carcinoma. In the multivariate analysis, only the circumscribed margin on sonography was an independent predicting factor for poorly differentiated thyroid carcinoma (odds ratio, 4.642). CONCLUSIONS: Both poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma commonly present as a relatively large malignant mass on sonography; however, poorly differentiated thyroid carcinoma showed a significantly higher incidence of a circumscribed margin and an oval-to-round shape than anaplastic thyroid carcinoma. Knowledge of sonographic characteristics will be useful for differentiation of poorly differentiated and anaplastic thyroid carcinomas.

Effect of menstrual cycle and menopausal status on apparent diffusion coefficient values and detectability of invasive ductal carcinoma on diffusion-weighted MRI.

The purpose of this study was to determine whether the apparent diffusion coefficient (ADC) and tumor detectability based on diffusion-weighted imaging (DWI) are affected by the menstrual cycle or menopausal status in breast cancer patients. Institutional review board approval was obtained, and the requirement for informed consent was waived. A total of 124 women with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast MRI with DWI were included in this study. Two radiologists retrospectively measured the ADCs of tumor and contralateral normal glandular tissue and scored the tumor detectability. The ADCs and detectability were compared to menstrual cycle and menopausal status, based on patient questionnaires. ADCs of tumors and contralateral tissue were significantly lower in postmenopausal women than in premenopausal women (P = 0.006 and P < 0.001, respectively). Tumor detectability did not differ significantly between the premenopausal and postmenopausal groups (P = 0.454). Normalized ADCs were not significantly lower in postmenopausal women compared to premenopausal women (P = 0.880). There was no statistically significant difference in the absolute, contralateral, and normalized ADCs (P = 0.091, 0.809, and 0.299, respectively), and the tumor detectability (P = 0.680) according to the menstrual cycle. Although ADCs of the IDC and normal glandular tissue in postmenopausal women were significantly lower than those in premenopausal women, the menstrual cycle did not affect tumor detectability and ADCs of IDC.

Correlations between apparent diffusion coefficient values of invasive ductal carcinoma and pathologic factors on diffusion-weighted MRI at 3.0 Tesla.

PURPOSE: To investigate correlations between apparent diffusion coefficient (ADC) values of invasive ductal carcinoma (IDC) and pathologic factors on diffusion-weighted MRI. We measured the ADC values of IDC of the breast and analyzed correlations between ADC values and factors such as tumor size, axillary lymph node status, histologic grade, estrogen receptor, progesterone receptor, and human epithelial growth factor 2 (HER2) using diffusion-weighted MRI at 3.0 Tesla (T). MATERIALS AND METHODS: We examined 110 patients with pathologically confirmed IDC using diffusion-weighted MRI at 3.0T. The ADC values of breast cancer were calculated using two b factors (0 and 1000 s/mm(2)). The relationship between ADC values and tumor size, histologic grade, axillary lymph node status, hormonal receptors, and HER2 were analyzed. RESULTS: The mean ADC value of IDC (n = 110) was 0.88 ± 0.15 × 10(-2) mm(2)/s. Tumors were subgrouped according to size (<2 cm, 2-5 cm, and ≥5 cm). Multiple comparisons within subgroups according to size showed that the ADC values for the three tumor size groups were significantly different (correlation coefficient = -0.007). The mean apparent diffusion coefficient of HER2-positive IDC was significantly higher than that of HER2-negative invasive ductal carcinoma (correlation coefficient = 0.218). CONCLUSION: ADC values of IDC were significantly correlated with tumor size and HER2 status.

Ultrasonographic hyperechoic lesions of the breast: are they always benign?

BACKGROUND: Most of the breast lesions show hypoechogenicity relative to fat on ultrasonography. The frequency and malignancy rate of hyperechoic lesions are not investigated in a large series. PURPOSE: To evaluate the frequency and malignancy rate of hyperechoic lesions on breast sonography and to investigate sonographic characteristics that may predict malignancy in hyperechoic breast lesions. MATERIAL AND METHODS: Radiologic reports of 16,416 patients who underwent breast sonography between 2007 and 2008 were searched using "hyperechoic", "echogenic" or "heterogeneous echoic" to describe lesions. Sonographic findings were evaluated according to the Breast Imaging Reporting and Data System lexicon. Clinical records including follow-up and pathologic findings were also reviewed. We calculated the frequency of hyperechoic lesions and their malignancy rate. Differences in sonographic appearances between benign and malignant lesions were also investigated. RESULTS: Among the 16,416 patients, 103 (0.6%) hyperechoic lesions were identified (mean size, 1.79 cm). Of these 103 lesions, 27 (26.2%) were pathologically evaluated and five (4.9%, 4 invasive ductal carcinoma and 1 mucinous carcinoma) were confirmed as malignant. Among the 819 malignant lesions diagnosed using sonography-guided core needle biopsy, five (0.6%) were hyperechoic. In benign lesions, fat necrosis and fibroadenoma were common pathologic diagnoses. Malignant lesions were more likely to have irregular shape (P = 0.003), non-parallel orientation (P = 0.002), non-circumscribed margin (P = 0.007), and a hypoechoic area (P = 0.027) than benign lesions. All hyperechoic carcinomas were seen as suspicious masses on mammograms. CONCLUSION: Hyperechoic masses are very rare and mostly benign. As an adjunct to mammography, the imaging findings reported here could help to avoid misdiagnosis for malignant hyperechoic lesion.

Sonographic and cytopathologic correlation of papillary thyroid carcinoma variants.

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer and constitutes more than 70% of thyroid malignancies. Although TNM staging is the most widely used parameter for determination of therapeutic plans, recent studies have suggested that different histopathologic variants of PTC can also have different clinical courses and patient prognoses. Sonographic criteria for PTC are well established and include a taller-than-wide shape, an irregular margin, microcalcifications, and marked hypoechogenicity. The role of sonography has expanded to enable the characterization of PTC variants based on their sonographic features. Tall cell and diffuse sclerosing variants appear to have more aggressive clinical courses with unfavorable prognoses, whereas the more recently described cribriform-morular and Warthin-like variants have relatively indolent clinical courses. The prognoses of patients with follicular, solid, columnar cell, and oncocytic variants are still controversial and may be similar to the prognosis of conventional PTC. Understanding the sonographic characteristics of PTC variants with clinicopathologic correlation may be helpful for suggesting an appropriate treatment plan.

Apparent diffusion coefficient in estrogen receptor-positive invasive ductal breast carcinoma: correlations with tumor-stroma ratio.

PURPOSE: To determine whether apparent diffusion coefficient (ADC) values vary according to tumor-stroma ratio, dominant stroma type, or presence of central fibrosis in estrogen receptor-positive breast cancer. MATERIALS AND METHODS: Institutional review board approval was obtained, and patient consent was waived. Sixty-one patients with estrogen receptor-positive invasive ductal carcinoma-not otherwise specified who underwent breast magnetic resonance (MR) imaging with diffusion-weighted (DW) imaging were included in this study. The ADC values of the lesions were measured. Two pathologists evaluated the tumor-stroma ratio, dominant stroma type (collagen, fibroblast, lymphocyte), and central fibrosis. Detectability on DW images was compared between the two groups according to the tumor-stroma ratio (stroma rich or stroma poor). Mean ADC values were retrospectively compared with the tumor-stroma ratio, dominant stroma type, and presence of a central fibrosis. Multiple linear regression analysis was performed to determine variables independently associated with ADC. RESULTS: On DW images, detectability was not significantly different between stroma-rich and stroma-poor groups (P = .244). ADC values were significantly lower in the stroma-poor group (P < .001). The mean ADC values in the collagen-dominant type were lower than in fibroblast-dominant or lymphocyte-dominant types (P = .021). In multiple linear regression analysis, tumor-stroma ratio (P = .007), tumor size (P = .007), and dominant stroma type (collagen dominant, P = .029) were independently correlated with ADC. CONCLUSION: In estrogen receptor-positive breast cancers, ADC values showed significant differences according to the tumor-stroma ratio and dominant stroma type.

Atypia of undetermined significance in thyroid fine-needle aspiration cytology: prediction of malignancy by US and comparison of methods for further management.

BACKGROUND: Further management for thyroid nodules with cytological atypia of undetermined significance (AUS) has made controversial conclusions. The aim of this study was to evaluate the most reliable ultrasonography (US) findings to predict malignancy in thyroid nodules with AUS, and to compare inconclusive rates of repeat fine-needle aspiration (rFNA) and core needle biopsy (CNB) in nodules with AUS. METHODS: We retrospectively reviewed cases of thyroid nodules with AUS from 8,421 US-guided fine-needle aspirations in our institution between 2010 and 2012. Nodules were confirmed either surgically or followed-up for at least 1 year and were compared based on nodule size, US findings, and US diagnosis to predict malignancy. Inconclusive rates of rFNA and CNB after initial AUS were compared. RESULTS: The incidence of AUS in all thyroid nodules was 3.2 % (273 of 8,421). Malignancies were identified in 42.1 % (64 of 152) nodules with surgery or sufficient follow-up. In univariate analysis, not-oval to round shape, irregular margin, taller-than-wide orientation, hypoechogenicity, marked hypoechogenicity, microcalcifications, and malignant US diagnosis were more frequent in actual malignancies (p < 0.05). In multivariate analysis, hypoechogenicity, marked hypoechogenicity, and malignant US diagnosis were significantly more frequent in malignancies (p < 0.05). With respect to further management of AUS, the inconclusive rate of CNB (17.6 %, 6/34) was significantly lower than that of rFNA (37.3 %; 44 of 118) (p = 0.032). CONCLUSIONS: Nodule echogenicity and US diagnosis can be predictive factors of malignancies for the thyroid nodules with cytological AUS. The CNB is more useful than rFNA for reducing the frequency of inconclusive results after initial AUS.