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.

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.

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.

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.

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.

Ultrasonographic Findings of an Implanted Absorbable Mesh in Patients with Breast Partial Resection: a Preliminary Study

PURPOSE: To present the ultrasonographic findings of an implanted absorbable mesh in patients who underwent breast partial resection. MATERIALS AND METHODS: We retrospectively analyzed the ultrasonographic findings of 18 patients who underwent breast partial resection with an absorbable mesh implant to minimize the breast deformity. Sonography was performed approximately 3 months after surgery (mean interval, 92 days). The presence of a capsule and cyst at the surgical site, the size of the cyst, internal content of the cyst, vascularity of the lesion, and presence of complications were analyzed. RESULTS: An ultrasound examination revealed a well-encapsulated cyst with regular capsule in 16 of the 18 patients. The longest diameter of the cyst varied from 3 cm to 10 cm. Among 16 cases that showed a well-encapsulated cyst, 11 cases showed an isoechoic nodular pattern in the cyst and in the remaining five cases, the internal nodular pattern was not seen. In two of the18 cases, an isoechoic nodular pattern without fluid content was seen for the lesions. A Doppler study revealed no vascularity in any of the lesions. CONCLUSION: Ultrasonographic findings of an implanted absorbable mesh, inserted in the surgical site to minimize breast deformity in patients that underwent breast partial resection, showed the presence of a well-encapsulated cyst with an internal isoechoic nodular pattern in the majority of the cases.

Multiple Myeloma of the Male Breast: A Case Report

Breast involvement of multiple myeloma is very rare, expecially in men. We describe the mammographic and sonographic findings of multiple myeloma involving the male breast.

Ultrasonographic and Mammographic Findings of Nodular Sclerosing Adenosis

PURPOSE: To evaluate the ultrasonographic and mammographic findings of cases of nodular adenosis. MATERIALS and METHODS: We evaluated 22 lesions with a pathologically proven nodular adenosis from five hospitals for three years. We excluded adenosis cases combined with other breast diseases. The findings of ultrasonography and mammography were retrospectively interpreted in consensus by two radiologists that were experienced in breast imaging according to the BI-RADS criteria. RESULTS: The age of the patients was 29-56 years with a mean age of 43.4 years. Ten lesions were biopsied with a 14-gauge core needle, seven lesions were biopsied with an 11-gauge vacuum-assisted mammotome and five lesions were removed by surgical excision. Mammography was performed in 15 patients and distinct abnormalities were seen in seven cases. These abnormalities consisted of an indistinct irregular mass, three circumscribed masses and three focal asymmetries. Calcifications were not seen in all of the masses. Ultrasonography was performed in 22 patients, revealing 13 irregular shaped lesions 8 oval shaped lesions and one round shape lesion. The margin was either circumscribed (n = 7) and not circumscribed (n = 15) in the lesions. The orientation of mass was parallel in 13 lesions and not parallel in 9 lesions. The boundary was an abrupt interface in all of the cases. The echogenecity of the mass was hypoechoic in 15 cases, isoechoic in 4 cases, hyperechoic in 2 cases and complex echogenic in one case. Nineteen of the cases showed no posterior feature and one case showed combined features. The final categories by the BI-RADS criteria were category 3 in three cases and category 4 in 19 cases (C4a 11, C4b 8). CONCLUSION: Nodular adenosis mostly presents as category 4 on ultrasonography. Therefore, a differential diagnosis with malignancy is difficult to determine. However, the findings of lesions highly suggestive of being malignant such as a spiculation or echogenic halo, are rare. On mammography, it is commonly obscured.

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.

The Role of the Use of US-guided Vacuum-Assisted Breast Biopsy for the Total Removal of Sonographic Evidence in Low- and High-Risk Benign and Malignant Breast Lesions

PURPOSE: To determine the role of the use of a US-guided vacuum-assisted biopsy for the removal of sonographic evidence (excisional mammotome) for low- and high-risk benign and malignant breast lesions. MATERIALS AND METHODS: We retrospectively reviewed the pathological results of 678 excisional mammotomes (611 low- and 46 high-risk benign and 21 malignant lesions). We compared the pathological results of the excisional mammotomes and the corresponding subsequent surgery of 27 high-risk benign (7/46 cases) and malignant (20/21 cases) lesions. We also reviewed the follow-up US findings of low- (306/611 cases) and high-risk benign lesions (33/39 cases). RESULTS: Fifteen of 27 (55.6%) surgical cases revealed a residual lesion on the excisional mammotome. There was no case of upgrade pathology seen for a surgical specimen. Follow-up sonography of 306 low-risk benign lesions showed a negative finding for 231 (75.2%) cases, post-biopsy changes in 56 (17.8%) cases, and residual lesions in 19 (5.7%) cases. None of the lesion was palpable. Follow-up sonography of 33 high-risk benign lesions revealed a negative finding in 28 (85%) cases, a post-biopsy scar in 4 (12%) cases, and a local recurrence in 1 (3%) case; none of the cases showed a residual lesion. CONCLUSION: We suggest that an excisional mammotome can replace surgical excision for low-risk cases and may avoid the immediate surgery for high-risk benign lesions; however, surgery is crucial for a malignancy.

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.