Feasibility of Ultrasound-Guided Localization for Clipped Metastatic Axillary Lymph Nodes After Neoadjuvant Chemotherapy in Breast Cancer Patients: A Pilot Study / 한국유방암학회지

We present our initial experience of ultrasound (US)-guided localization of clipped metastatic axillary lymph nodes (LNs) following neoadjuvant chemotherapy (NAC). We evaluated US visibility and the successful excision rate of clipped LN after NAC in 29 consecutive patients with breast cancer. US-guided localization of clipped nodes was performed in 22 patients on the day of surgery, while seven patients underwent surgery without localization. The clips were identified in all patients with residual metastatic LNs and 6 of 12 (50%) patients without residual metastatic LNs on US. Six patients without visible clips underwent US-guided localization at the presumed previous clip insertion site. The successful excision rate of 22 LNs with localization was 100% (even though 3 of them were non-sentinel LNs) and 57% (4/7) without localization. Regardless of the presence of visible residual metastatic LNs on US after NAC, successful excision of the clipped LN with US-guided localization is feasible.

Analysis of Prognoses according to Breast MRI Results in Patients with Axillary Lymph Node Metastases from an Unknown Primary Origin

Purpose@#To compare the prognosis of patients with axillary adenocarcinoma from an unknown primary (ACUPax) origin with negative MRI results and those with MRI-detected primary breast cancers. @*Materials and Methods@#The breast MRI images of 32 patients with ACUPax without signs of primary breast cancer on mammography and ultrasound (US) were analyzed. Spot compression-magnification mammography and second-look US were performed for the area of MRI abnormality in patients with positive results; any positive findings corresponding to the MRI abnormality were confirmed by biopsy. If suspicious MRI lesions could not be localized on mammography or US, MR-guided biopsy or excision biopsy after MR-guided localization was performed. We compared the prognosis of patients with negative breast MRI with that for patients with MRI-detected primary breast cancers. @*Results@#Primary breast cancers were confirmed in 8 (25%) patients after breast MRI. Primary breast cancers were not detected on MRI in 24 (75%) patients, including five cases of false-positive MRI results. Twenty-three patients underwent axillary lymph node dissection (ALND) followed by whole breast radiation therapy (WBRT) and chemotherapy (n=17) or subsequent chemotherapy only (n=2). Recurrence or distant metastasis did not occur during follow up in 7/8 patients with MRI-detected primary breast cancers and 22/24 patients with negative MRI results. Regional recurrence or distant metastasis did not occur in any MR-negative patient who received adjuvant chemotherapy after ALND and WBRT. @*Conclusion@#The prognoses of MR-negative patients with ACUPax who received ALND and WBRT followed by chemotherapy were as good as those of patients with MRI-detected primary breast cancers.

Combined use of shear-wave elastography and Doppler ultrasonography in equivocal fibroepithelial lesions of the breast diagnosed by core needle biopsy

Purpose@#The aim of this study was to evaluate the diagnostic value of shear-wave elastography (SWE) combined with Doppler ultrasonography (US) in selecting equivocal breast fibroepithelial lesions (FELs) for follow-up without further excision. @*Methods@#A retrospective analysis was conducted of 88 patients with equivocal breast FELs (FELs with the possibility of both fibroadenoma [FA] and phyllodes tumor [PT]) diagnosed by core needle biopsy (CNB). For post-CNB treatment, surgical or vacuum-assisted excision was performed on 88 equivocal FELs, of which 56 were diagnosed as FAs and 32 as PTs on histopathology. Mean elasticity (Emean) and vascularity were determined using SWE and Doppler US. The diagnostic performances of B-mode US, SWE, and Doppler US were calculated to differentiate FAs and PTs in the excised equivocal FELs. @*Results@#In the excised equivocal FELs diagnosed by CNB, FAs showed significantly lower median Emean values (36.4 vs. 66.7 kPa, P=0.005) and more frequent low vascularity (0–1 vessel flow signal) (P60.9 kPa and high vascularity (≥2 vessel flows) showed a sensitivity and negative predictive value of 100%, as well as better performance in other diagnostic values than B-mode US alone (Breast Imaging Reporting and Data System ≥4A) (all P<0.05). @*Conclusion@#Equivocal breast FELs showing both low elasticity and low vascularity were not upgraded to PTs upon further excision. Therefore, the combination of SWE and color Doppler US mode might help select patients with equivocal FELs for whom further excision is unnecessary.

Impact of Skeletal Muscle Loss and Visceral Obesity Measured Using Serial CT on the Prognosis of Operable Breast Cancers in Asian Patients

Objective@#This study aimed to investigate the impact of baseline values and temporal changes in body composition parameters, including skeletal muscle index (SMI) and visceral adipose tissue area (VAT), measured using serial computed tomography (CT) imaging on the prognosis of operable breast cancers in Asian patients. @*Materials and Methods@#This study retrospectively included 627 Asian female (mean age ± standard deviation [SD], 53.6 ± 8.3 years) who underwent surgery for stage I–III breast cancer between January 2011 and September 2012. Body composition parameters, including SMI and VAT, were semi-automatically calculated on baseline abdominal CT at the time of diagnosis and follow-up CT for post-treatment surveillance. Serial changes in SMI and VAT were calculated as the delta values. Multivariable Cox regression analysis was used to evaluate the association of baseline and delta SMI and VAT values with disease-free survival. @*Results@#Among 627 patients, 56 patients (9.2%) had breast cancer recurrence after a median of 40.5 months. The mean value ± SD of the baseline SMI and baseline VAT were 43.7 ± 5.8 cm2 /m2 and 72.0 ± 46.0 cm2 , respectively. The mean value of the delta SMI was -0.9 cm2 /m2 and the delta VAT was 0.5 cm2 . The baseline SMI and VAT were not significantly associated with disease-free survival (adjusted hazard ratio [HR], 0.983; 95% confidence interval [CI], 0.937–1.031; p = 0.475 and adjusted HR, 1.001; 95% CI, 0.995–1.006; p = 0.751, respectively). The delta SMI and VAT were also not significantly associated with disease-free survival (adjusted HR, 0.894; 95% CI, 0.766–1.043; p = 0.155 and adjusted HR, 1.001; 95% CI, 0.989–1.014; p = 0.848, respectively). @*Conclusion@#Our study revealed that baseline and early temporal changes in SMI and VAT were not independent prognostic factors regarding disease-free survival in Asian patients undergoing surgery for breast cancer.

Atypical Ductal Hyperplasia: Risk Factors for Predicting Pathologic Upgrade on Excisional Biopsy

Purpose@#To determine the incidence of atypical ductal hyperplasia (ADH) in needle biopsy and the upgrade rate to carcinoma, and to evaluate difference in findings between the upgrade and non-upgrade groups. @*Materials and Methods@#Among 9660 needle biopsies performed over 48 months, we reviewed the radiologic and histopathologic findings of ADH and compared the differences in imaging findings (mammography and breast US) and biopsy methods between the upgrade and non-upgrade groups. @*Results@#The incidence of ADH was 1.7% (169/9660). Of 112 resected cases and 30 cases followed-up for over 2 years, 35 were upgraded to carcinoma (24.6%, 35/142). The upgrade rates were significantly different according to biopsy methods: US-guided core needle biopsy (US-CNB) (40.7%, 22/54) vs. stereotactic-vacuum-assisted biopsy (S-VAB) (16.0%, 12/75) vs. US-guided VAB (US-VAB) (7.7%, 1/13) (p = 0.002). Multivariable analysis showed that only US-CNB (odds ratio = 5.19, 95% confidence interval: 2.16–13.95, p < 0.001) was an independent predictor for pathologic upgrade. There was no upgrade when a sonographic mass was biopsied by US-VAB (n = 7) @*Conclusion@#The incidence of ADH was relatively low (1.7%) and the upgrade rate was 24.6%. Surgical excision should be considered because of the considerable upgrade rate, except in the case of US-VAB.

Imaging Protocol and Criteria for Evaluation of Axillary Lymph Nodes in the NAUTILUS Trial / 한국유방암학회지

Axillary ultrasonography (US) is the most commonly used imaging modality for nodal evaluation in patients with breast cancer. No Axillary Surgical Treatment in Clinically Lymph Node-Negative Patients after Ultrasonography (NAUTILUS) is a prospective, multicenter, randomized controlled trial investigating whether sentinel lymph node biopsy (SLNB) can be safely omitted in patients with clinically and sonographically node-negative T1–2 breast cancer treated with breast-conserving therapy. In this trial, a standardized imaging protocol and criteria were established for the evaluation of axillary lymph nodes. Women lacking palpable lymph nodes underwent axillary US to dismiss suspicious nodal involvement.Patients with a round hypoechoic node with effaced hilum or indistinct margins were excluded. Patients with T1 tumors and a single node with a cortical thickness ≥ 3 mm underwent US-guided biopsy. Finally, patients with negative axillary US findings were included. The NAUTILUS axillary US nodal assessment criteria facilitate the proper selection of candidates who can omit SLNB.

Understanding Silicone Breast Implant-Associated Complications for Radiologists

With the increase in the number of cases of silicone implant insertion either for cosmetic surgery or breast reconstruction after mastectomy, it is not unusual to encounter patients with silicone implants in clinical settings. Recently, the first case of breast implant-associated anaplastic large cell lymphoma was reported in Korea. In addition to previously known complications, such as implant rupture or contracture, the number of implant-associated imaging examinations has also increased. Considering this background, radiologists should have sufficient knowledge about the type of examination required in patients who have undergone implant insertion and imaging findings to correctly identify implant-associated complications. In this article, various complications of silicone implants are discussed, including various imaging findings, which radiologists should know.

Magnetic Resonance Imaging-Guided Breast Biopsy in Korea: A 10-Year Follow-Up Experience / 한국유방암학회지

Purpose@#To evaluate the accuracy of magnetic resonance imaging (MRI)-guided breast biopsy. @*Methods@#We retrospectively reviewed the clinical data of 111 consecutive patients referred for MRI-guided breast biopsy after mammography and breast ultrasound between May 2009 and April 2019. After excluding 37 patients without follow-up images (> 2 years), 74 patients (74 lesions) were finally included. We reviewed the histologic results of MRI-guided biopsy and subsequent surgery, post-biopsy management, and breast cancer development during followup. We investigated the false-negative rate, ductal carcinoma in situ (DCIS) underestimation, atypical ductal hyperplasia (ADH) underestimation rate, and technical failure rate of MRIguided biopsy. @*Results@#Among 74 scheduled MRI-guided biopsies, six were canceled because biopsy was deemed unnecessary, while three failed due to technical difficulties (technical failure rate:3/68, 4.4%). MRI-guided biopsy was performed in 65 patients, of which 18 patients were diagnosed with malignant lesions, 46 with benign lesions, and one with ADH bordering on DCIS. Subsequent surgery (n = 27) showed DCIS underestimation in three cases (3/7, 43%), ADH underestimation in two cases (1/2, 50%), as well as seven concordant benign and 11 concordant malignant lesions. The overall false-negative rate was 4.3% (2/46). Thirty-eight out of 48 benign lesions were followed-up (median period, 5.8 years; interquartile range, 4.1 years) without subsequent surgery. Thirty-seven concordant benign lesions were stable (n = 27) or disappeared (n = 10); however, the size of one discordant benign lesion increased on follow-up MRI and it was diagnosed as DCIS after 1 year. @*Conclusion@#MRI-guided biopsy is an accurate method for exclusion of malignancy with a very low false-negative rate.

Diffusion-Weighted Magnetic Resonance Imaging for Breast Cancer Screening in High-Risk Women: Design and Imaging Protocol of a Prospective Multicenter Study in Korea / 한국유방암학회지

Purpose@#Interest in unenhanced magnetic resonance imaging (MRI) screening for breast cancer is growing due to concerns about gadolinium deposition in the brain and the high cost of contrast-enhanced MRI. The purpose of this report is to describe the protocol of the Diffusion-Weighted Magnetic Resonance Imaging Screening Trial (DWIST), which is a prospective, multicenter, intraindividual comparative cohort study designed to compare the performance of mammography, ultrasonography, dynamic contrast-enhanced (DCE) MRI, and diffusion-weighted (DW) MRI screening in women at high risk of developing breast cancer. @*Methods@#A total of 890 women with BRCA mutation or family history of breast cancer and lifetime risk ≥ 20% are enrolled. The participants undergo 2 annual breast screenings with digital mammography, ultrasonography, DCE MRI, and DW MRI at 3.0 T. Images are independently interpreted by trained radiologists. The reference standard is a combination of pathology and 12-month follow-up. Each image modality and their combination will be compared in terms of sensitivity, specificity, accuracy, positive predictive value, rate of invasive cancer detection, abnormal interpretation rate, and characteristics of detected cancers. The first participant was enrolled in April 2019. At the time of manuscript submission, 5 academic medical centers in South Korea are actively enrolling eligible women and a total of 235 women have undergone the first round of screening. Completion of enrollment is expected in 2022 and the results of the study are expected to be published in 2026.Discussion: DWIST is the first prospective multicenter study to compare the performance of DW MRI and conventional imaging modalities for breast cancer screening in high-risk women. DWIST is currently in the patient enrollment phase.

Magnetic Resonance Imaging-Guided Breast Biopsy in Korea: A 10-Year Follow-Up Experience / 한국유방암학회지

Purpose@#To evaluate the accuracy of magnetic resonance imaging (MRI)-guided breast biopsy. @*Methods@#We retrospectively reviewed the clinical data of 111 consecutive patients referred for MRI-guided breast biopsy after mammography and breast ultrasound between May 2009 and April 2019. After excluding 37 patients without follow-up images (> 2 years), 74 patients (74 lesions) were finally included. We reviewed the histologic results of MRI-guided biopsy and subsequent surgery, post-biopsy management, and breast cancer development during followup. We investigated the false-negative rate, ductal carcinoma in situ (DCIS) underestimation, atypical ductal hyperplasia (ADH) underestimation rate, and technical failure rate of MRIguided biopsy. @*Results@#Among 74 scheduled MRI-guided biopsies, six were canceled because biopsy was deemed unnecessary, while three failed due to technical difficulties (technical failure rate:3/68, 4.4%). MRI-guided biopsy was performed in 65 patients, of which 18 patients were diagnosed with malignant lesions, 46 with benign lesions, and one with ADH bordering on DCIS. Subsequent surgery (n = 27) showed DCIS underestimation in three cases (3/7, 43%), ADH underestimation in two cases (1/2, 50%), as well as seven concordant benign and 11 concordant malignant lesions. The overall false-negative rate was 4.3% (2/46). Thirty-eight out of 48 benign lesions were followed-up (median period, 5.8 years; interquartile range, 4.1 years) without subsequent surgery. Thirty-seven concordant benign lesions were stable (n = 27) or disappeared (n = 10); however, the size of one discordant benign lesion increased on follow-up MRI and it was diagnosed as DCIS after 1 year. @*Conclusion@#MRI-guided biopsy is an accurate method for exclusion of malignancy with a very low false-negative rate.

Diffusion-Weighted Magnetic Resonance Imaging for Breast Cancer Screening in High-Risk Women: Design and Imaging Protocol of a Prospective Multicenter Study in Korea / 한국유방암학회지

Purpose@#Interest in unenhanced magnetic resonance imaging (MRI) screening for breast cancer is growing due to concerns about gadolinium deposition in the brain and the high cost of contrast-enhanced MRI. The purpose of this report is to describe the protocol of the Diffusion-Weighted Magnetic Resonance Imaging Screening Trial (DWIST), which is a prospective, multicenter, intraindividual comparative cohort study designed to compare the performance of mammography, ultrasonography, dynamic contrast-enhanced (DCE) MRI, and diffusion-weighted (DW) MRI screening in women at high risk of developing breast cancer. @*Methods@#A total of 890 women with BRCA mutation or family history of breast cancer and lifetime risk ≥ 20% are enrolled. The participants undergo 2 annual breast screenings with digital mammography, ultrasonography, DCE MRI, and DW MRI at 3.0 T. Images are independently interpreted by trained radiologists. The reference standard is a combination of pathology and 12-month follow-up. Each image modality and their combination will be compared in terms of sensitivity, specificity, accuracy, positive predictive value, rate of invasive cancer detection, abnormal interpretation rate, and characteristics of detected cancers. The first participant was enrolled in April 2019. At the time of manuscript submission, 5 academic medical centers in South Korea are actively enrolling eligible women and a total of 235 women have undergone the first round of screening. Completion of enrollment is expected in 2022 and the results of the study are expected to be published in 2026.Discussion: DWIST is the first prospective multicenter study to compare the performance of DW MRI and conventional imaging modalities for breast cancer screening in high-risk women. DWIST is currently in the patient enrollment phase.

A Survey on Current Trends of Breast Imaging Practices in Korea

PURPOSE@#This study aimed to analyze the current practices of breast imaging among Korean radiologists.@*MATERIALS AND METHODS@#We invited members of the Korean Society of Breast Imaging (KSBI) working as breast radiologists to participate in a survey on the current practices in breast imaging, and investigated how quality assurance (QA), medical audits, and imaging-histologic discordance were conducted.@*RESULTS@#The survey involved 312 members of the KSBI, and 116 (37%) responded to the 21 questions in the questionnaire. Most of the respondents were women (87%), aged below 50 years (82.7%), and working at university or tertiary hospitals (68.1%), who had varying levels of experience in breast imaging. Of the 116 respondents, 114 (96.6%) followed the Breast Imaging Reporting and Data System (BI-RADS) to interpret breast imaging. Out of 116, 72 (62.1%) interpreted 20 or more mammograms per day, 84 (72.4%) performed 10–30 breast ultrasound scans per day, and 65 (56%) interpreted fewer than 5 breast MRI scans per day. Among the respondents, 82% performed mammography QA, 76.9% evaluated imaging-histologic correlations, and only 38.9% performed medical audits.@*CONCLUSION@#The institutions and working patterns of breast radiologists were diverse. Although many respondents did not conduct medical audits, most of them followed BI-RADS when interpreting breast imaging, performing QA, and evaluating imaging-histologic correlations.

MRI Criteria for Predicting Invasive Lesions in Biopsy-Proven Ductal Carcinoma in Situ

PURPOSE@#To evaluate the criteria for predicting invasive lesions with preoperative breast MRI in ductal carcinoma in situ (DCIS) histopathologically diagnosed with biopsy.@*MATERIALS AND METHODS@#We retrospectively analyzed the preoperative MRI findings of 80 percutaneous biopsy-proven DCIS. The morphological type, enhancement distribution and kinetics, and extent of the lesions were analyzed. We compared the results of pure DCIS and DCIS with invasive lesions. We evaluated the MRI criteria for predicting DCIS with invasive lesions and assessed its diagnostic performance.@*RESULTS@#Of the 80 DCIS lesions analyzed, 27 contained co-existing invasive lesions and 49 were pure DCIS. No residual lesions after biopsy were seen in 4 cases. DCIS with invasive lesions showed washout kinetics more frequently and to a larger extent than did pure DCIS (p = 0.030 and p = 0.048, respectively). Using enhancement kinetics and the lesion cut-off value of 4 cm yielded the highest diagnostic performance, with 92.6% sensitivity and 93.8% negative predictive value for predicting invasive lesions.@*CONCLUSION@#Washout kinetics and the lesion extent of at least 4 cm are useful criteria for the prediction of co-existing invasive lesions in patients with DCIS diagnosed with biopsy.

Additional lesions seen in magnetic resonance imaging of breast cancer patients: the role of second-look ultrasound and imaging-guided interventions

PURPOSE: The purpose of this study was to investigate the final outcomes of magnetic resonance imaging (MRI)-identified additional lesions (MRALs) in breast cancer patients and the role of second-look ultrasound (SLUS) and imaging-guided interventions. METHODS: We analyzed breast cancer patients with MRALs on preoperative MRI between January and June 2012. MRALs were defined as additional lesions suspected on MRI but not suspected on mammograms or ultrasound. The malignancy rate of MRALs, MRI-based Breast Imaging Reporting and Database System (BI-RADS) category, positional relationship with the index cancer, MRI-concordant lesion visibility on SLUS, performance of imaging-guided interventions, and total mastectomy (TM) rates were evaluated for the confirmed lesions. RESULTS: Among the 119 confirmed lesions, SLUS and imaging-guided interventions were performed in 94 (79.0%) and 82 cases (68.9%), respectively. The malignancy rate was 68.1% (81 of 119), and was significantly higher in BI-RADS 4C-5 lesions than in 4A-4B lesions (94.6% vs. 56.1%, P < 0.01) and in ipsilateral same-quadrant lesions than in contralateral lesions (84.2% vs. 33.3%, P < 0.01). The lesion visibility rate on SLUS was 90.4%. The malignancy rate was not significantly different according to lesion visibility on SLUS. The TM rate in the 98 cases with ipsilateral MRALs was 37.8%, while it was significantly lower in patients who underwent an imaging-guided intervention than in those who did not (27.9% vs. 54.1%, P=0.017). CONCLUSION: MRALs show a high probability of malignancy, especially if they are ipsilateral. SLUS and imaging-guided interventions can eliminate many unnecessary TMs.

Effect of a Deep Learning Framework-Based Computer-Aided Diagnosis System on the Diagnostic Performance of Radiologists in Differentiating between Malignant and Benign Masses on Breast Ultrasonography

OBJECTIVE: To investigate whether a computer-aided diagnosis (CAD) system based on a deep learning framework (deep learning-based CAD) improves the diagnostic performance of radiologists in differentiating between malignant and benign masses on breast ultrasound (US). MATERIALS AND METHODS: B-mode US images were prospectively obtained for 253 breast masses (173 benign, 80 malignant) in 226 consecutive patients. Breast mass US findings were retrospectively analyzed by deep learning-based CAD and four radiologists. In predicting malignancy, the CAD results were dichotomized (possibly benign vs. possibly malignant). The radiologists independently assessed Breast Imaging Reporting and Data System final assessments for two datasets (US images alone or with CAD). For each dataset, the radiologists' final assessments were classified as positive (category 4a or higher) and negative (category 3 or lower). The diagnostic performances of the radiologists for the two datasets (US alone vs. US with CAD) were compared. RESULTS: When the CAD results were added to the US images, the radiologists showed significant improvement in specificity (range of all radiologists for US alone vs. US with CAD: 72.8–92.5% vs. 82.1–93.1%; p < 0.001), accuracy (77.9–88.9% vs. 86.2–90.9%; p = 0.038), and positive predictive value (PPV) (60.2–83.3% vs. 70.4–85.2%; p = 0.001). However, there were no significant changes in sensitivity (81.3–88.8% vs. 86.3–95.0%; p = 0.120) and negative predictive value (91.4–93.5% vs. 92.9–97.3%; p = 0.259). CONCLUSION: Deep learning-based CAD could improve radiologists' diagnostic performance by increasing their specificity, accuracy, and PPV in differentiating between malignant and benign masses on breast US.

Current Practices in Breast Magnetic Resonance Imaging: a Survey Involving the Korean Society of Breast Imaging

PURPOSE: To report on the current practices in breast magnetic resonance imaging (MRI) in Korea. MATERIALS AND METHODS: We invited the 68 members of the Korean Society of Breast Imaging who were working in hospitals with available breast MRI to participate in a survey on how they performed and interpreted breast MRI. We asked one member from each hospital to respond to the survey. A total of 22 surveys from 22 hospitals were analyzed. RESULTS: Out of 22 hospitals, 13 (59.1%) performed at least 300 breast MRI examinations per year, and 5 out of 22 (22.7%) performed > 1200 per year. Out of 31 machines, 14 (45.2%) machines were 1.5-T scanners and 17 (54.8%) were 3.0-T scanners. All hospitals did contrast-enhanced breast MRI. Full-time breast radiologists supervised the performance and interpreted breast MRI in 19 of 22 (86.4%) of hospitals. All hospitals used BI-RADS for MRI interpretation. For computer-aided detection (CAD), 13 (59.1%) hospitals sometimes or always use it and 9 (40.9%) hospitals did not use CAD. Two (9.1%) and twelve (54.5%) hospitals never and rarely interpreted breast MRI without correlating the mammography or ultrasound, respectively. The majority of respondents rarely (13/21, 61.9%) or never (5/21, 23.8%) interpreted breast MRI performed at an outside facility. Of the hospitals performing contrast-enhanced examinations, 15 of 22 (68.2%) did not perform MRI-guided interventional procedures. CONCLUSION: Breast MRI is extensively performed in Korea. The indication and practical patterns are diverse. The information from this survey would provide the basis for the development of Korean breast MRI practice guidelines.

Breast Imaging Reporting and Data System Category 3 Lesions Detected on Whole-Breast Screening Ultrasound / 한국유방암학회지

PURPOSE: This study assessed the incidence and cancer rate of probably benign lesions detected on bilateral whole-breast screening ultrasound (US), which corresponded to US Breast Imaging Reporting and Data System (BI-RADS) category 3, and evaluated the proper management of those lesions. METHODS: This study was approved by the Institutional Review Board in our institution, which waived informed patient consent. We retrospectively reviewed US images of 1,666 patients who underwent bilateral whole-breast screening US as a supplemental screening test to negative screening mammography or screening US only. The incidence, clinical course, and cancer rate of screening US-detected probably benign lesions corresponding to US BI-RADS category 3 were investigated, and the size and multiplicity of screening US-detected category 3 lesions were evaluated. RESULTS: Probably benign lesions corresponding to US BI-RADS category 3 were detected in 689 of 1,666 patients (41.4%) who underwent screening US. Among them, 653 had follow-up US images for at least 24 months, and among these 653, 190 (29.1%) had multiple bilateral category 3 lesions. Moreover, 539 of 1,666 patients (32.4%) had lesions ≤1 cm in size and 114 of 1,666 (6.8%) had lesions >1 cm (median, 0.82 cm; range, 0.3–4.2 cm). Four of the 653 patients (0.6%) showed suspicious interval changes and were categorized into BI-RADS category 4. Biopsy analysis confirmed only one lesion as invasive ductal carcinoma at the 6-month follow-up; another lesion was an intraductal papilloma and the remaining two were fibroadenomas. Overall cancer rate of the screening US-detected BI-RADS category 3 lesions was 0.2%. CONCLUSION: The incidence of category 3 lesions detected on screening US only was very high, but the cancer rate was very low. Therefore, in an average-risk population, routine screening US is preferable over short-term follow-up for BI-RADS category 3 lesions detected on whole-breast screening US.

Radiologic Findings of Primary Mucinous Cystadenocarcinoma of the Breast: A Report of Two Cases and a Literature Review / 한국유방암학회지

Primary mucinous cystadenocarcinoma (MCA) of the breast is a rare but pathologically distinct breast tumor. There have been some case reports on primary MCA of the breast; however, they have all focused on pathologic findings. Here, we report the radiologic findings of two cases of MCA along with a review of the literature. Breast MCA shows a circumscribed mass with some calcifications on mammography, an intracystic solid mass without increased vascularity or a vascular stalk on ultrasound, and a heterogeneously enhancing mass within a rim-enhancing cyst with intermediate signal intensity on T2-weighted magnetic resonance imaging. These radiologic findings and the presence of mucin in the percutaneous biopsy specimen should suggest the possibility of MCA in the differential diagnosis of a breast tumor.

Screening Ultrasound in Women with Negative Mammography: Outcome Analysis

PURPOSE: To show the results of an audit of screening breast ultrasound (US) in women with negative mammography in a single institution and to analyze US-detected cancers within a year and interval cancers. MATERIALS AND METHODS: During the year of 2006, 1974 women with negative mammography were screened with US in our screening center, and 1727 among them had pathologic results or any follow up breast examinations more than a year. We analyzed the distribution of Breast Imaging Reporting and Data System (BI-RADS) category and the performance outcome through follow up. RESULTS: Among 1727 women (age, 30-76 years, median 49.5 years), 1349 women (78.1%) showed dense breasts on mammography, 762 (44.1%) had previous breast US, and 25 women (1.4%) had a personal history of breast cancers. Test negatives were 94.2% (1.627/1727) [BI-RADS category 1 in 885 (51.2%), 2 in 742 (43.0%)]. The recall rate (=BI-RADS category 3, 4, 5) was 5.8%. Eight cancers were additionally detected with US (yield, 4.6 per 1000). The sensitivity, specificity, and positive predictive value (PPV1, PPV2) were 88.9%, 94.6%, 8.0%, and 28.0%, respectively. Eight of nine true positive cancers were stage I or in-situ cancers. One interval cancer was stage I cancer from BI-RADS category 2. CONCLUSION: Screening US detected 4.6 additional cancers among 1000. The recall rate was 5.8%, which is in lower bound of acceptable range of mammography (5-12%), according to American College of Radiology standard.

Prognostic Significance of a Complete Response on Breast MRI in Patients Who Received Neoadjuvant Chemotherapy According to the Molecular Subtype

OBJECTIVE: To evaluate the relationship between response categories assessed by magnetic resonance imaging (MRI) or pathology and survival outcomes, and to determine whether there are prognostic differences among molecular subtypes. MATERIALS AND METHODS: We evaluated 174 patients with biopsy-confirmed invasive breast cancer who had undergone MRI before and after neoadjuvant chemotherapy, but before surgery. Pathology findings were classified as a pathologic complete response (pCR) or a non-pCR, and MRI findings were designated as a radiologic CR (rCR) or a non-rCR. We evaluated overall and subtype-specific associations between clinicopathological factors including the assessment categories and recurrence, using the Cox proportional hazards model. RESULTS: There were 41 recurrences (9 locoregional and 32 distant recurrences). There were statistically significant differences in recurrence outcomes between patients who achieved a radiologic or a pCR and patients who did not achieve a radiologic or a pCR (recurrence hazard ratio, 11.02; p = 0.018 and recurrence hazard ratio, 3.93; p = 0.022, respectively). Kaplan-Meier curves for recurrence-free survival showed that triple-negative breast cancer was the only subtype that showed significantly better outcomes in patients who achieved a CR compared to patients who did not achieve a CR by both radiologic and pathologic assessments (p = 0.004 and 0.001, respectively). A multivariate analysis found that patients who achieved a rCR and a pCR did not display significantly different recurrence outcomes (recurrence hazard ratio, 2.02; p = 0.505 and recurrence hazard ratio, 1.12; p = 0.869, respectively). CONCLUSION: Outcomes of patients who achieved a rCR were similar to those of patients who achieved a pCR. To evaluate survival difference according to molecular subtypes, a larger study is needed.