Characterization of Breast Lesions: Comparison of Digital Breast Tomosynthesis and Ultrasonography

OBJECTIVE: To compare the diagnostic performance of digital breast tomosynthesis (DBT) and conventional breast ultrasound (US) to characterize breast lesions as benign or malignant. MATERIALS AND METHODS: A total of 332 women, presenting for screening examinations or for breast biopsy between March and June 2012 were recruited to undergo digital mammography (DM), DBT, and breast US examination. Among them, 113 patients with 119 breast lesions depicted on DM were finally included. Three blinded radiologists performed an enriched reader study and reviewed the DBT and US images. Each reader analyzed the lesions in random order, assigned Breast Imaging Reporting and Data System (BI-RADS) descriptors, rated the images for the likelihood of malignancy (%) and made a BI-RADS final assessment. Diagnostic accuracy, as assessed by the area under the receiver operating characteristic curve, sensitivity, and specificity of DBT and US were compared. RESULTS: Among the 119 breast lesions depicted on DM, 75 were malignant and the remaining 44 were benign. The average diagnostic performance for characterizing breast lesions as benign or malignant in terms of area under the curve was 0.899 for DBT and 0.914 for US (p = 0.394). Mean sensitivity (97.3% vs. 98.7%, p = 0.508) and specificity (44.7% vs. 39.4%, p = 0.360) were also not significantly different. CONCLUSION: Digital breast tomosynthesis may provide similar reader lesion characterization performance to that of US for breast lesions depicted on DM.

Isolated Post-Transplantation Lymphoproliferative Disease Involving the Breast and Axilla as Peripheral T-cell Lymphoma

Post-transplantation lymphoproliferative disorders (PTLDs) are a heterogeneous group of diseases that represent serious complications following immunosuppressive therapy for solid organ or hematopoietic-cell recipients. In contrast to B-cell PTLD, T-cell PTLD is less frequent and is not usually associated with Epstein Barr Virus infection. Moreover, to our knowledge, isolated T-cell PTLD involving the breast is extremely rare and this condition has never been reported previously in the literature. Herein, we report a rare case of isolated T-cell PTLD of the breast that occurred after a patient had been treated for allogeneic peripheral blood stem cell transplantation due to acute myeloblastic leukemia.

Comparison of Diagnostic Performance of US Elastography and Conventional B-mode US in Differentiation of Breast Lesions

PURPOSE: The purpose of this study was to compare the diagnostic performance of ultrasound (US) elastography and conventional B-mode US for discrimination between benign and malignant breast lesions. MATERIALS AND METHODS: During a 13-month period, 277 women with 335 sonographically visible breast lesions who were scheduled to undergo biopsy were examined with US elastography. Elastographic findings were classified as benign or malignant based on the area ratio, with 1.00 as the threshold. Findings on conventional B-mode US were classified according to the BI-RADS category, as follows: lesions of BI-RADS categories 2 and 3 were considered benign, while those in categories 4 and 5 were considered malignant. Statistical analysis included sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and ROC curve analysis for comparison of the diagnostic performance of US elastography and conventional B-mode US. RESULTS: Of the 335 breast lesions, 85 (25.4%) showed malignancy on pathology. Findings on B-mode US showed malignancy in 264 (78.8%) and elastographic findings showed malignancy in 102 (30.4%). The sensitivity, specificity, PPV, NPV, and accuracy of B-mode US and elastography were 98.8%, 28.0%, 31.8%, 98.6%, and 79.4% and 69.4%, 81.2%, 57.8%, 88.8%, and 79.4%, respectively. Elastography showed significantly higher specificity and PPV and lower sensitivity and NPV, compared with B-mode US (p < 0.001). The area under the ROC curve (AUC value) was 0.761 for elastography, and 0.634 for B-mode US (p < 0.001). CONCLUSIONS: US elastography can improve specificity and PPV of B-mode US, but with significant sacrifice of sensitivity and NPV. Therefore, US elastography may complement B-mode US for differentiation of breast masses.

Current Trends in Breast Ultrasonography

In the last 30 years, technical improvements have directly contributed to expanding sonographic breast imaging applications into the most important adjunctive imaging modality for breast evaluation. Most of these advances have related to improvements in sonographic gray-scale image resolution and contrast, but some applications such as color Doppler imaging, elastography, optical imaging, or three-dimensional ultrasounds have resulted in sonographic information that is uniquely different from grayscale imaging. The current spectrum of new breast sonographic techniques not only offers information uniquely different from gray-scale imaging but also involves hardware advances that affect the method of image production. In this article, we discuss the current trends in breast ultrasonography focusing on the advances to further improve accuracy for breast lesion diagnosis.

Underestimation of Ductal Carcinoma In situ on Sonographically Guided Core Needle Biopsy of the Breast

PURPOSE: The purpose of this study was to determine the underestimation rate of ductal carcinoma in situ (DCIS) on sonographically guided 14-gauge core needle biopsy of the breast and to investigate the factors associated with this underestimation. MATERIALS AND METHODS: We retrospectively reviewed 2990 consecutive lesions that underwent sonographically guided 14-gauge core needle biopsy between January 2005 and December 2008. Among them, 61 lesions were pathologically proven to be DCIS (2.04%). A total of 50 DCIS lesions (mean patient age: 50.7 years old, age range: 36-79 years old) that underwent surgical resection were included in this study. After surgery, the lesion proven to be invasive was defined as being in the underestimated group and the lesion proven to DCIS was defined as being in the correctly diagnosed group. We determined the underestimation rate of DCIS and we retrospectively reviewed and compared the clinical, pathologic and radiologic features of the two groups. RESULTS: The underestimation rate of DCIS was found to be 28% (14 of 50 lesions). The underestimation of DCIS was significantly frequent for a clinically palpable lesion (78.6% (11/14) vs. 30.5% (11/36), respectively, p = 0.002). The sonographically maximal diameter of a lesion was significantly larger in the underestimated group than that in the accurately diagnosed group (28.4 +/- 14.0 mm vs. 17.6 +/- 10.3 mm, respectively, p = 0.017) and underestimation was significantly frequent when the sonographic lesion size was > 20 mm (p = 0.012). There was no significant difference in terms of age, the lesion type, the Breast Imaging-Reporting and Data System (BI-RADS) category or the pathologic features between the two groups. CONCLUSION: The underestimation rate of DCIS was 28% for sonographically guided 14-gauge core needle biopsy of the breast. Clinical symptoms such as a palpable lesion and a sonographic lesion size > 20 mm were the factors related with the underestimation of DCIS.

Elastography of the Breast: Imaging Techniques and Pitfalls in Interpretation

Ultrasound (US) elastography is a tool that indicates the hardness of a lesion. Recent studies using elastography with freehand compression have shown similar diagnostic performance to conventional US in differentiating benign lesions from malignant breast masses. On the other hand, the acquired information is not quantitative, and the reliability of the imaging technique to correctly compress the tissue depends on the skill of the operator, resulting in substantial interobserver variability during data acquisition and interpretation. To overcome this, shear wave elastography was developed to provide quantitative information on the tissue elasticity. The system works by remotely inducing mechanical vibrations through the acoustic radiation force created by a focused US beam. This review discusses the principles and examination techniques of the two types of elastography systems and provides practical points to reduce the interobserver variability or errors during data acquisition and interpretation.

Pseudoaneurysm of the Breast after 14-Gauge Core Biopsy: Case Report

A pseudoaneurysm of the breast after a core needle biopsy is an extremely rare vascular complication. We report one case of a breast pseudoaneurysm that developed after an ultrasound-guided core needle biopsy. The ultrasound appearance, prevention and treatment of a breast pseudoaneurysm are discussed.

Benign Lesions with Posterior Acoustic Shadowing on Ultrasound: The Pathologic Correlation

A breast lesion with posterior acoustic shadowing is often encountered on sonography and this finding is generally accepted as a sign of malignancy. Although its detection is important for differentiating a malignant breast mass from a benign breast mass, posterior acoustic shadowing is the result of attenuation of the sound beam by a desmoplastic host response to breast cancer rather than the posterior acoustic shadowing being due to the tumor itself. Therefore, many breast conditions that contain fibrous elements also can induce some degree of acoustic shadowing. In this article, we present various benign breast lesions that display posterior acoustic shadowing and we discuss the radiologic findings along with the pathologic correlation.

Non-Mass Image-Forming Low Echoic Areas on Breast US: Pathologic Correlation

PURPOSE: We wanted to analyze the mammographic and clinical findings of the non-mass image-forming low echoic areas seen on breast ultrasonography (US) and investigate their pathologic results. MATERIALS AND METHODS: Sixty-nine patients with 72 non-mass image-forming low echoic areas seen on breast US and who had undergone mammography and biopsy were included in this study. The mammographic findings were divided into 2 groups: 1) the negative or probably benign group and 2) the suspicious for malignancy group. The US findings were divided into 3 groups: focal, segmental and diffuse distributions. The clinical findings were divided into 2 groups: the non-palpable and palpable groups. We investigated the pathologic results according to each group. RESULTS: Of the 72 lesions, 49 (68.1%) were benign and 23 (31.9%) were malignant. On the mammography, 42 (93.3%) of the 45 negative or probably benign findings and 7 (25.9%) of 27 suspicious for malignancy findings were pathologically benign (p < 0.001). On the US, 38 (76%) of the 50 focal distributions and 11 (52.4%) of 21 segmental distributions were benign (p = 0.090). Thirty (73.2%) of the 41 nonpalpable lesions and 19 (61.3%) of the 31 palpable lesions were benign (p = 0.609). CONCLUSIONS: A non-mass image-forming low echoic area seen on breast US was malignant at a higher rate when it was found in conjunction with suspicious mammographic finding. There was no significant correlation between the distribution of the non-mass image-forming low echoic areas on US or their palpability and the pathologic results.

Evaluation of Tumor Angiogenesis with a Second-Generation US Contrast Medium in a Rat Breast Tumor Model

OBJECTIVE: Tumor angiogenesis is an important factor for tumor growth, treatment response and prognosis. Noninvasive imaging methods for the evaluation of tumor angiogenesis have been studied, but a method for the quantification of tumor angiogenesis has not been established. This study was designed to evaluate tumor angiogenesis in a rat breast tumor model by the use of a contrast-enhanced ultrasound (US) examination with a second-generation US contrast agent. MATERIALS AND METHODS: The alkylating agent 19N-ethyl-N-nitrosourea (ENU) was injected into the intraperitoneal cavity of 30-day-old female Sprague-Dawley rats. Three to four months later, breast tumors were detected along the mammary lines of the rats. A total of 17 breast tumors larger than 1 cm in nine rats were evaluated by gray-scale US, color Doppler US and contrast-enhanced US using SonoVue. The results were recorded as digital video images; time-intensity curves and hemodynamic parameters were analyzed. Pathological breast tumor specimens were obtained just after the US examinations. The tumor specimens were stained with hematoxylin and eosin (H & E) and the expression of CD31, an endothelial cell marker, was determined by immunohistochemical staining. We also evaluated the pathological diagnosis of the tumors and the microvessel density (MVD). Spearman's correlation and the Kruskal-Wallis test were used for the analysis. RESULTS: The pathological diagnoses were 11 invasive ductal carcinomas and six benign intraductal epithelial proliferations. The MVD did not correlate with the pathological diagnosis. However, blood volume (BV) showed a statistically significant correlation with MVD (Spearman's correlation, p < 0.05). CONCLUSION: Contrast-enhanced US using a second-generation US contrast material was useful for the evaluation of tumor angiogenesis of breast tumors in the rat.

US-Guided Vacuum-Assisted Biopsy of Microcalcifications in Breast Lesions and Long-Term Follow-Up Results

OBJECTIVE: To evaluate the diagnostic accuracy of the use of an ultrasonography (US)-guided vacuum-assisted biopsy for microcalcifications of breast lesions and to evaluate the efficacy of the use of US-guided vacuum-assisted biopsy with long-term follow-up results. MATERIALS AND METHODS: US-guided vacuum-assisted biopsy cases of breast lesions that were performed between 2002 and 2006 for microcalcifications were retrospectively reviewed. A total of 62 breast lesions were identified where further pathological confirmation was obtained or where at least two years of mammography follow-up was obtained. These lesions were divided into the benign and malignant lesions (benign and malignant group) and were divided into underestimated group and not-underestimated lesions (underestimated and not-underestimated group) according to the diagnosis after a vacuum-assisted biopsy. The total number of specimens that contained microcalcifications was analyzed and the total number of microcalcification flecks as depicted on specimen mammography was analyzed to determine if there was any statistical difference between the groups. RESULTS: There were no false negative cases after more than two years of follow-up. Twenty-nine lesions were diagnosed as malignant (two invasive carcinomas and 27 carcinoma in situ lesions). Two of the 27 carcinoma in situ lesions were upgraded to invasive cancers after surgery. Among three patients diagnosed with atypical ductal hyperplasia, the diagnosis was upgraded to a ductal carcinoma in situ after surgery in one patient. There was no statistically significant difference in the number of specimens with microcalcifications and the total number of microcalcification flecks between the benign group and malignant group of patients and between the underestimated group and not-underestimated group of patients. CONCLUSION: US-guided vacuum-assisted biopsy can be an effective alternative to stereotactic-guided vacuum-assisted biopsy in cases where microcalcifications are visible with the use of high-resolution US.

The Influence of Training on Breast Ultrasound Expertise

PURPOSE: This study was designed to evaluate the effectiveness of the training experience to develop expertise for breast ultrasound. The same group of radiology residents was evaluated before and after training on the use of the Breast Imaging Reporting and Data System (BI-RADS) to develop breast imaging expertise. MATERIALS AND METHODS: An evaluation set of breast ultrasonography images of pathologically confirmed lesions that consisted of 100 masses (54 benign and 46 malignant masses) without clinical information was developed. Two experienced breast radiologists independently reviewed cases to reach a consensus. Six radiology residents (four second-year residents and two third-year residents) trained one month to interpret breast ultrasound examinations, and to read and to review teaching files with expertise. The residents evaluated the examination set according to BI-RADS for shape, orientation, margin, lesion-boundary, echo pattern, posterior echo features, surrounding tissue, calcification and final assessment before and after the training. Training performance was measured by means of agreement (k) and diagnostic performance. RESULTS: After training, the second-year residents showed statistically significant increased agreement as compared to the experts for 15 of the total 36 BI-RADS descriptors. The third-year residents showed increased agreement for three of the 18 descriptors. The mean sensitivity for the residents was 94.2% (range, 89.1-100%) before training and the mean sensitivity increased to 97.8% (range, 95.7-100%) after training. The mean specificity was 50.6% (range, 40.7-59.3%) before training and the mean specificity decreased to 42.0% (range, 31.5-51.9%) after training. CONCLUSION: In this study, the use of breast ultrasonography training improved the ability of residents to determine lesion description, final assessment and coherence.

Nonpalpable Breast Masses: Evaluation by US Elastography

OBJECTIVE: To compare the diagnostic performances of conventional ultrasound (US) and US elastography for the differentiation of nonpalpable breast masses, and to evaluate whether elastography is helpful at reducing the number of benign biopsies, using histological analysis as a reference standard. MATERIALS AND METHODS: Conventional US and real-time elastographic images were obtained for 100 women who had been scheduled for a US-guided core biopsy of 100 nonpalpable breast masses (83 benign, 17 malignant). Two experienced radiologists unaware of the biopsy and clinical findings analyzed conventional US and elastographic images by consensus, and classified lesions based on degree of suspicion regarding the probability of malignancy. Results were evaluated by receiver operating characteristic curve analysis. In addition, the authors investigated whether a subset of lesions was categorized as suspicious by conventional US, but as benign by elastography. RESULTS: Areas under the ROC curves (Az values) were 0.901 for conventional US and 0.916 for elastography (p = 0.808). For BI-RADS category 4a lesions, 44% (22 of 50) had an elasticity score of 1 and all were found to be benign. CONCLUSION: Elastography was found to have a diagnostic performance comparable to that of conventional US for the differentiation of nonpalpable breast masses. The authors conclude that BI-RADS category 4a lesions with an elasticity score of 1 probably do not require biopsy.

Breast Imaging Reporting and Data System (BI-RADS) US lexicon and Final Assessment Category for Solid Breast Masses: the Rates of Inter- and Intraobserver Agreement

PURPOSE: To evaluate the rates of inter- and intraobserver agreement of the BI-RADS US lexicon. MATERIALS AND METHODS: Two radiologists reviewed 60 sonograms of solid breast masses to evaluate interobserver agreement. After four weeks, the radiologists reinterpreted the series to evaluate the intraobserver agreement. The radiologists described shape, orientation, margin, lesion boundary, echo pattern, posterior acoustic features and microcalcifications. Final assessment categories and management plans were suggested for each case. The rates of inter- and intraobserver agreements were measured by the use of kappa statistics. RESULTS: Interobserver agreement ranged from the highest for orientation (k=0.65) and shape (k=0.61) to the lowest for posterior acoustic features (k=0.42). For the final assessment categories (k=0.46) and management (k=0.49), interobserver agreements were moderate. Intraobserver agreement ranged from the highest for microcalcifications in mass (k=0.90, 0.82) and orientation (k=0.87, 0.83) and the lowest for echo patterns (k=0.62, 0.57) and posterior acoustic features (k=0.59, 0.65). In the final assessment category and management, intraobserver agreements were substantial or nearly complete (k=0.65-0.83). CONCLUSION: There were variable ranged inter- and intraobserver agreements in the description of the BI-RADS US lexicon of solid breast masses. Among them, margin and lesion boundary showed lower agreements. A modification of the BI-RADS US lexicon with more detailed guidelines, followed by continuous education, are suggested.

Breast Sarcoidosis Appearing as a Primary Manifestation of Sarcoidosis: A Case Report

Breast sarcoidosis is a rare disease entity and may have similar imaging findings as a breast malignancy. We report here a case of primary breast sarcoidosis that was diagnosed as nonspecific inflammation by sonography-guided 14-G automated needle biopsy. A directional vacuum assisted biopsy was helpful for a correct diagnosis.

Pure and Mixed Tubular Carcinoma of the Breast: Mammographic and Sonographic Differential Features

OBJECTIVE: We wanted to evaluate the mammographic and sonographic differential features between pure (PT) and mixed tubular carcinoma (MT) of the breast. MATERIALS AND METHODS: Between January 1998 and May 2004, 17 PTs and 14 MTs were pathologically confirmed at our institution. The preoperative mammography (n = 26) and sonography (n = 28) were analyzed by three radiologists according to BI-RADS. RESULTS: On mammography, a mass was not detected in eight patients with PT and in one patient with MT (57% vs. 8%, respectively, p = 0.021), which was statistically different. The other findings on mammography and sonography showed no statistical differences between the PT and MT, although the numerical values were different. When the lesions were detected mammographically, an irregularly shaped mass with a spiculated margin was more frequently found in the MT than in the PT (100% vs. 83%, respectively, p = 0.353). On sonography, all 28 patients presented with a mass and most lesions showed as not being circumscribed, hypoechoic masses with an echogenic halo. Surrounding tissue changes and posterior shadowing were more frequently found in the MT than in the PT (75% vs. 50%, respectively, p = 0.253, 58% vs. 19%, respectively, p = 1.000). An oval shaped mass was more frequently found in the PT than in the MT (44% vs. 25%, respectively; p = 0.434). CONCLUSION: PT and MT cannot be precisely differentiated on mammography and sonography. However, the absence of a mass on mammography or the presence of an oval shaped mass would favor the diagnosis of PT. An irregularly shaped mass with surrounding tissue change and posterior shadowing on sonography would favor the diagnosis of MT and also a less favorable prognosis.

Sonographically-Guided 14-Gauge Core Needle Biopsy for Papillary Lesions of the Breast

OBJECTIVE: We wanted to assess the need for surgical excising papillary lesions of the breast that were diagnosed upon sonographically guided 14-gauge core needle biopsy. MATERIALS AND METHODS: Sixty-nine women (age range: 25-74 years, mean age: 51.7 years) with 69 papillary lesions (4.9%) were diagnosed and followed after performing sonographically guided 14-gauge core needle biopsies. Surgical excision was performed for 44 (64%) of 69 papillary lesions, and 25 lesions were followed with imaging studies (range: 6-46 months, mean: 17.9 months). The histologic findings upon core biopsy were compared with the surgical, imaging and follow-up findings. RESULTS: Core needle biopsies of 69 lesions yielded tissue that was classified as benign for 43 lesions, atypical for 18 lesions and malignant for eight lesions. Of the 43 lesions that yielded benign papilloma upon core needle biopsy, one had intraductal papillary carcinoma found upon surgery. An immediate surgical biopsy was recommended for this lesion because of the imaging-histologic discordance. No additional carcinoma was found during the imaging follow-up. Surgical excision was performed for 17 atypical papillary lesions, and this revealed intraductal (n = 6) or invasive (n = 2) papillary carcinoma in 8 (47%) lesions. Of the seven intraductal papillary carcinomas, surgery revealed invasive papillary carcinoma in one (14%). CONCLUSION: Our results suggest that papillary lesions of the breast that are diagnosed as benign upon sonographically guided 14-gauge core needle biopsy can be followed when the results are concordant with the imaging findings.

Breast Cancer from the Excisional Scar of a Benign Mass

Breast cancer developing from a surgical scar is rare; this type of malignancy has been reported in only 12 cases to date. Herein, we report on a 52-year-old female who developed infiltrating ductal carcinoma in a surgical scar following excision of a benign mass. Two years previously, the patient underwent surgery and radiotherapy for invasive ductal carcinoma of the contralateral breast. The initial appearance of the scar was similar to fat necrosis; it was observed to be progressively shrinking on follow-up sonography. On the two year follow-up ultrasound, the appearance changed, an angular margin and vascularity at the periphery of the scar were noted. A biopsy and subsequent excision of the scar were performed; the diagnosis of infiltrating ductal carcinoma of the scar was confirmed.

Imaging and the Clinical-Pathologic Features of Invasive Micropapillary Carcinoma of the Breast

PURPOSE: The purpose of this study was to describe the mammographic and sonographic appearances and the clinical-pathologic features of invasive micropapillary carcinoma. MATERIALS AND METHODS: Between December 1999 and March 2005, among the 3,109 patients who underwent operation for breast cancer, 25 patients proved to have invasive micropaillary carcinoma. Among the 25 patients, we included 22 patients (mean age: 48, range: 26-77 years) who had undergone preoperative mammography and ultrasound. The mammographic and sonographic findings of the lesions were analyzed retrospectively. The pathologic findings were analyzed via the clinical records and pathology reports. RESULTS: Patients manifested with a palpable mass (77%, 17/22), bloody nipple discharge (14%, 3/22) or incidental lesion on the screening mammography (9%, 2/22). On mammography, a mass with an irregular (86%, 12/14) shape and an indistinct (43%, 6/14) or spiculated (43%, 6/14) margin was the most common findings on mammography. On sonography, a hypoechoic (91%, 20/22) mass with irregular shape (73%, 16/22) and an indistinct (32%, 7/22) or microlobulated (32%, 7/22) margin was the most common finding. Pathologically, axillary lymph node metastasis was present in 73% (16/22) of the patients. CONCLUSION: Invasive micropapillary carcinoma appeared an irregular shaped mass with an indistinct margin mass or microcalcifications on mammography and/or sonography. The tumors were frequently associated with axillary lymph node metastasis.

Analysis of Previous Screening Examinations for Patients with Breast Cancer

PURPOSE: We wanted to improve the quality of subsequent screening by reviewing the previous screening of breast cancer patients. MATERIALS AND METHODS: Twenty-four breast cancer patients who underwent previous screening were enrolled. All 24 took mammograms and 15 patients also took sonograms. We reviewed the screening retrospectively according to the BI-RADS criteria and we categorized the results into false negative, true negative, true positive and occult cancers. We also categorized the causes of false negative cancers into misperception, misinterpretation and technical factors and then we analyzed the attributing factors. RESULTS: Review of the previous screening revealed 66.7% (16/24) false negative, 25.0% (6/24) true negative, and 8.3% (2/24) true positive cancers. False negative cancers were caused by the mammogram in 56.3% (9/16) and by the sonogram in 43.7% (7/16). For the false negative cases, all of misperception were related with mammograms and this was attributed to dense breast, a lesion located at the edge of glandular tissue or the image, and findings seen on one view only. Almost all misinterpretations were related with sonograms and attributed to loose application of the final assessment. CONCLUSION: To improve the quality of breast screening, it is essential to overcome the main causes of false negative examinations, including misperception and misinterpretation. We need systematic education and strict application of final assessment categories of BI-RADS. For effective communication among physicians, it is also necessary to properly educate them about BI-RADS.