Imaging of breast masses

Diagnostic performance improvement with combined use of proteomics biomarker assay and breast ultrasound

PURPOSE

To investigate the combined use of blood-based 3-protein signature and breast ultrasound (US) for validating US-detected lesions.

METHODS

From July 2011 to April 2020, women who underwent whole-breast US within at least 6 months from sampling period were retrospectively included. Blood-based 3-protein signature (Mastocheck®) value and US findings were evaluated. Following outcome measures were compared between US alone and the combination of Mastocheck® value with US: sensitivity, specificity, positive predictive value (PPV), negative predictive value, area under the receiver operating characteristic curve (AUC), and biopsy rate.

RESULTS

Among the 237 women included, 59 (24.9%) were healthy individuals and 178 (75.1%) cancer patients. Mean size of cancers was 1.2 ± 0.8 cm. Median value of Mastocheck® was significantly different between nonmalignant (- 0.24, interquartile range [IQR] - 0.48, - 0.03) and malignant lesions (0.55, IQR - 0.03, 1.42) (P < .001). Utilizing Mastocheck® value with US increased the AUC from 0.67 (95% confidence interval [CI] 0.61, 0.73) to 0.81 (95% CI 0.75, 0.88; P < .001), and specificity from 35.6 (95% CI 23.4, 47.8) to 64.4% (95% CI 52.2, 76.6; P < .001) without loss in sensitivity. PPV was increased from 82.2 (95% CI 77.1, 87.3) to 89.3% (95% CI 85.0, 93.6; P < .001), and biopsy rate was significantly decreased from 79.3 (188/237) to 72.1% (171/237) (P < .001). Consistent improvements in specificity, PPV, and AUC were observed in asymptomatic women, in women with dense breast, and in those with normal/benign mammographic findings.

CONCLUSION

Mastocheck® is an effective tool that can be used with US to improve diagnostic specificity and reduce false-positive findings and unnecessary biopsies.

BI-RADS 3: Current and Future Use of Probably Benign

PURPOSE OF REVIEW

Probably benign (BI-RADS 3) causes confusion for interpreting physicians and referring physicians and can induce significant patient anxiety. The best uses and evidence for using this assessment category in mammography, breast ultrasound, and breast MRI will be reviewed; the reader will have a better understanding of how and when to use BI-RADS 3.

RECENT FINDINGS

Interobserver variability in the use of BI-RADS 3 has been documented. The 5th edition of the BI-RADS atlas details the appropriate use of BI-RADS 3 for diagnostic mammography, ultrasound, and MRI, and discourages its use in screening mammography. Data mining, elastography, and diffusion weighted MRI have been evaluated to maximize the accuracy of BI-RADS 3.

SUMMARY

BI-RADS 3 is an evolving assessment category. When used properly, it reduces the number of benign biopsies while allowing the breast imager to maintain a high sensitivity for the detection of early stage breast cancer.

Multimodal ultrasound computer-assisted tomography: An approach to the recognition of breast lesions

The research here presented aims at developing a new, promising method for the imaging diagnostics of breast lesions - ultrasound tomography (UST). A currently implemented device enables the reconstruction three complementary images for each coronal breast section. Based on in vivo breast examination, the authors developed an approach to breast diagnostics which employs ultrasound transmission and reflection tomography imaging. The obtained transmission images of ultrasound speed distribution show good correlation of glandular tissue areas with their visualization on MRI images. The results also allow a prediction that the implemented UST device offering fusion of reconstructed images may contribute to achieving a new standard for breast cancer diagnostics through non-invasive, fast and cheap screening tests.

Application of 3D and 2D quantitative shear wave elastography (SWE) to differentiate between benign and malignant breast masses

As breast cancer tissues are stiffer than normal tissues, shear wave elastography (SWE) can locally quantify tissue stiffness and provide histological information. Moreover, tissue stiffness can be observed on three-dimensional (3D) colour-coded elasticity maps. Our objective was to evaluate the diagnostic performances of quantitative features in differentiating breast masses by two-dimensional (2D) and 3D SWE. Two hundred ten consecutive women with 210 breast masses were examined with B-mode ultrasound (US) and SWE. Quantitative features of 3D and 2D SWE were assessed, including elastic modulus standard deviation (E_SD^E) measured on SWE mode images and E_SD^U measured on B-mode images, as well as maximum elasticity (E_max). Adding quantitative features to B-mode US improved the diagnostic performance (p < 0.05) and reduced false-positive biopsies (p < 0.0001). The area under the receiver operating characteristic curve (AUC) of 3D SWE was similar to that of 2D SWE for E_SD^E (p = 0.026) and E_SD^U (p = 0.159) but inferior to that of 2D SWE for E_max (p = 0.002). Compared with E_SD^U, E_SD^E showed a higher AUC on 2D (p = 0.0038) and 3D SWE (p = 0.0057). Our study indicates that quantitative features of 3D and 2D SWE can significantly improve the diagnostic performance of B-mode US, especially 3D SWE E_SD^E, which shows considerable clinical value.

Additional diagnostic value of shear-wave elastography and color Doppler US for evaluation of breast non-mass lesions detected at B-mode US

OBJECTIVE

To evaluate the diagnostic value of shear-wave elastography (SWE) and colour Doppler ultrasound (US) for evaluation of breast non-mass lesions (NMLs) detected by B-mode US.

METHODS

This retrospective study enrolled 116 NMLs (42 benign, 74 malignant). For each lesion, B-mode US, SWE and colour Doppler US were performed. Mean elasticity (E mean), maximum elasticity (E max) and vascularity were assessed by SWE and Doppler US. Diagnostic performances of B-mode US, SWE and Doppler US were calculated to differentiate benign and malignant NMLs.

RESULTS

In benign NMLs, average E mean and E max were lower, and low vascularity (no flow or only one vessel flow) was more frequent (P < 0.001). When BI-RADS category 4a NMLs were downgraded to category 3 with 'E mean of 85.1 kPa or less' and/or 'low vascularity', specificities increased (69.0-90.5 %; P < 0.001), without significant loss in sensitivities (97.3-100 %). When these 4a NMLs were downgraded by the combination of SWE and Doppler US, all downgraded NMLs (59.3 %, 19/32) were confirmed as benign.

CONCLUSIONS

Addition of SWE and colour Doppler US to B-mode US improved diagnostic performances in differentiating benign and malignant NMLs. This study suggests that the combination of SWE and colour Doppler may help patients with BI-RADS category 4a NMLs avoid unnecessary biopsies.

KEY POINTS

• B-mode US features of malignant and benign NMLs may overlap. • SWE and colour Doppler provides useful information about breast NMLs. • SWE and colour Doppler may decrease unnecessary biopsies of breast NMLs.

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.

Interobserver agreement on the interpretation of automated whole breast ultrasonography

Purpose:

The purpose of this study was to prospectively evaluate the interobserver agreement on lesion characterization and the final assessment of automated whole breast ultrasonography (ABUS) images.

Methods:

Between March and August 2012, 172 women underwent bilateral ABUS before biopsy guided by handheld ultrasonography (HHUS) and mammography. A total of 206 breast lesions were confirmed histopathologically by biopsy. Three-dimensional volume data from ABUS scans were analyzed by two radiologists without the knowledge of HHUS results or patient clinical information. The two readers described the type, shape, orientation, margin, echogenicity, posterior acoustic features, and categorization of the final assessment of detected breast lesions. Kappa statistics were used to analyze the described characteristics of the breast lesions detected by both of the two readers.

Results:

Of the 206 histopathologically confirmed lesions, reader 1 detected 166 lesions and reader 2 detected 150 lesions. A total of 145 lesions were detected by both readers using ABUS images. There was substantial agreement on shape (κ=0.707), and moderate agreement on type, margin, mass orientation, echogenicity, and posterior acoustic features (κ=0.592, 0.438, 0.472, 0.524, and 0.541, respectively). Breast Imaging Reporting and Data System final assessment values yielded a kappa value of 0.3971 when category subdivisions 4A, 4B, and 4C were included. With respect to the C2, C3, C4, and C5 categories, the interobserver agreement was moderate (κ=0.505).

Conclusion:

ABUS is a promising diagnostic tool with a good interobserver agreement, comparable to that of HHUS.

Shear-wave elastography improves the specificity of breast US: the BE1 multinational study of 939 masses

PURPOSE

To determine whether adding shear-wave (SW) elastographic features could improve accuracy of ultrasonographic (US) assessment of breast masses.

MATERIALS AND METHODS

From September 2008 to September 2010, 958 women consented to repeat standard breast US supplemented by quantitative SW elastographic examination in this prospective multicenter institutional review board-approved, HIPAA-compliant protocol. B-mode Breast Imaging Reporting and Data System (BI-RADS) features and assessments were recorded. SW elastographic evaluation (mean, maximum, and minimum elasticity of stiffest portion of mass and surrounding tissue; lesion-to-fat elasticity ratio; ratio of SW elastographic-to-B-mode lesion diameter or area; SW elastographic lesion shape and homogeneity) was performed. Qualitative color SW elastographic stiffness was assessed independently. Nine hundred thirty-nine masses were analyzable; 102 BI-RADS category 2 masses were assumed to be benign; reference standard was available for 837 category 3 or higher lesions. Considering BI-RADS category 4a or higher as test positive for malignancy, effect of SW elastographic features on area under the receiver operating characteristic curve (AUC), sensitivity, and specificity after reclassifying category 3 and 4a masses was determined.

RESULTS

Median participant age was 50 years; 289 of 939 (30.8%) masses were malignant (median mass size, 12 mm). B-mode BI-RADS AUC was 0.950; eight of 303 (2.6%) BI-RADS category 3 masses, 18 of 193 (9.3%) category 4a lesions, 41 of 97 (42%) category 4b lesions, 42 of 57 (74%) category 4c lesions, and 180 of 187 (96.3%) category 5 lesions were malignant. By using visual color stiffness to selectively upgrade category 3 and lack of stiffness to downgrade category 4a masses, specificity improved from 61.1% (397 of 650) to 78.5% (510 of 650) (P<.001); AUC increased to 0.962 (P=.005). Oval shape on SW elastographic images and quantitative maximum elasticity of 80 kPa (5.2 m/sec) or less improved specificity (69.4% [451 of 650] and 77.4% [503 of 650], P<.001 for both), without significant improvement in sensitivity or AUC.

CONCLUSION

Adding SW elastographic features to BI-RADS feature analysis improved specificity of breast US mass assessment without loss of sensitivity.

Automated ultrasound of the breast for diagnosis: interobserver agreement on lesion detection and characterization

OBJECTIVE

The purpose of this study was to prospectively evaluate interobserver agreement on lesion detection and characterization in the review of automated ultrasound images of the breast by five radiologists.

SUBJECTS AND METHODS

From August to October 2009, bilateral whole-breast ultrasound examinations were performed with an automated technique and with a handheld device for 55 women consecutively scheduled to undergo diagnostic ultrasound. Three-dimensional volume data from automated ultrasound were reviewed by five radiologists, who were unaware of the results of ultrasound with a handheld device and mammography and of the clinical information. If a lesion was detected with automated ultrasound, clock-face position, distance from the nipple, largest diameter, and BI-RADS final assessment category were evaluated. If the lesion was a mass, shape, orientation, margin, echogenicity, and posterior feature were analyzed. Intraclass correlation coefficients and kappa statistics were used for statistical analysis.

RESULTS

At least two observers identified 145 lesions with automated ultrasound. Among 725 possible detections, 587 (81%) detections were made. Individual investigators detected between 74% (107/145) and 88% (127/145) of the lesions. The rate of detection of lesions larger than 1.2 cm was 92%. Most lesions detected only with handheld ultrasound (11/12, 92%) or automated ultrasound (34/36, 94%) were cysts or probably benign masses. All intraclass correlation coefficients for lesion location and size exceeded 0.75, indicating high reliability. Substantial agreement was found for mass shape (κ = 0.71), orientation (κ = 0.72), margin (κ = 0.61), and BI-RADS final assessment category (κ = 0.63).

CONCLUSION

Detection of lesions larger than 1.2 cm in greatest diameter was reliable. High reliability was obtained for reporting lesion size and location. Substantial agreement was obtained for description of key feature and final assessment category.

Radiotransparency of polyvinylpyrrolidone-hydrogel and hydrogel breast implants: a quantitative analysis with mastectomy specimens

Breast cancer is the most common cancer in women. Past evidence suggested that women with silicone implants who had cancer presented with more advanced disease and had the worst prognosis due to difficulty visualizing early lesions on mammography. Hence, new filling materials have been developed. In this study, 10 mastectomy specimens were used. Mammograms of specimens alone and specimens covering polyvinylpyrrolidone-hydrogel and hydrogel implants were performed. The variables studied were number of mammograms necessary to examine each specimen, kilovolts and milliamperes of each mammogram, number of isolated microcalcifications, microcalcification clusters and macroscopic calcifications, and rarefaction areas. No significant differences were found in number of mammograms (p = 0.439), isolated microcalcifications (p = 0.178), macrocalcifications (p = 1.0), and presence of rarefaction areas (p = 0.368). The difference in number of microcalcification clusters was significant (p = 0.0498). Significant differences (p < 0.001) also were observed in the kilovolts and milliamperes of the mammograms performed for specimens alone versus those with implants. Polyvinylpyrrolidone-hydrogel and hydrogel breast implants allow adequate visualization of mammary glands at the expense of greater radiation doses, although it must be considered that the experimental situation does not fully match the real clinical setting.

Cystic breast masses and the ACRIN 6666 experience

Masses due to cystic lesions of the breast are extremely common findings on mammography, ultrasonography, and magnetic resonance imaging. Although many of these lesions can be dismissed as benign simple cysts, requiring intervention only for symptomatic relief, complex cystic and solid masses require biopsy. Perhaps, the most challenging are complicated cysts, that is, cysts with internal debris. When the debris is mobile or a fluid-debris level is seen, complicated cysts can be dismissed as benign findings. As an isolated finding, homogeneous complicated cysts can be classified as probably benign, with intervention only considered with interval development or enlargement, abscess is suspected, or if suspicious features develop. When multiple and bilateral complicated and simple cysts are present (ie, at least three, with at least one in each breast), a benign, BI-RADS 2, assessment is usually appropriate. Clustered microcysts are common benign findings in pre- and perimenopausal women, though short-interval surveillance may be appropriate for many such lesions in post-menopausal women, particularly if the lesion is new or rather small or deep (ie, diagnostic uncertainty).

Breast reconstruction with parenchymal cross after giant lipoma removal

Lipomas are benign tumors composed of mature fat, usually encapsulated. A literature review showed that the vast majority of lipomas are small, weighing only a few grams, and grow slowly. According to Hawary et al. (Ann Saudi Med 19(2):174-176, 1999) a giant breast lipoma is characterized by a lesion of at least 5 cm in one dimension and weighs more than 500 g. We present a rare case of a giant breast lipoma with slow growth over 22 years that compromised the entire hemithorax through the right iliac fossa. A 49-year-old woman was referred to our plastic surgery unit because of complaints of severe breast asymmetry due to an enormous mass in the right breast. Twenty-two years earlier she had noticed a soft, mobile, nonpulsatile mass in the inferior quadrant of her right breast. She did not look for medical treatment for all those years for fear of it being cancer. Ultrasound suggested a lipomatous lesion. Open mass biopsy revealed lipoma. The patient underwent a whole mass resection, reconstruction with a parenchymal cross flap, and left breast symmetrization with an inverted T technique. An excellent result with a high degree of patient satisfaction was achieved with the procedure. Parenchymal cross flaps seem to be an option in these situations.

Stereotactic mammography imaging combined with 3D US imaging for image guided breast biopsy

Stereotactic X-ray mammography (SM) and ultrasound (US) guidance are both commonly used for breast biopsy. While SM provides three-dimensional (3D) targeting information and US provides real-time guidance, both have limitations. SM is a long and uncomfortable procedure and the US guided procedure is inherently two dimensional (2D), requiring a skilled physician for both safety and accuracy. The authors developed a 3D US-guided biopsy system to be integrated with, and to supplement SM imaging. Their goal is to be able to biopsy a larger percentage of suspicious masses using US, by clarifying ambiguous structures with SM imaging. Features from SM and US guided biopsy were combined, including breast stabilization, a confined needle trajectory, and dual modality imaging. The 3D US guided biopsy system uses a 7.5 MHz breast probe and is mounted on an upright SM machine for preprocedural imaging. Intraprocedural targeting and guidance was achieved with real-time 2D and near real-time 3D US imaging. Postbiopsy 3D US imaging allowed for confirmation that the needle was penetrating the target. The authors evaluated 3D US-guided biopsy accuracy of their system using test phantoms. To use mammographic imaging information, they registered the SM and 3D US coordinate systems. The 3D positions of targets identified in the SM images were determined with a target localization error (TLE) of 0.49 mm. The z component (x-ray tube to image) of the TLE dominated with a TLEz of 0.47 mm. The SM system was then registered to 3D US, with a fiducial registration error (FRE) and target registration error (TRE) of 0.82 and 0.92 mm, respectively. Analysis of the FRE and TRE components showed that these errors were dominated by inaccuracies in the z component with a FREz of 0.76 mm and a TREz of 0.85 mm. A stereotactic mammography and 3D US guided breast biopsy system should include breast compression for stability and safety and dual modality imaging for target localization. The system will provide preprocedural x-ray mammography information in the form of SM imaging along with real-time US imaging for needle guidance to a target. 3D US imaging will also be available for targeting, guidance, and biopsy verification immediately postbiopsy.

Sonographic differentiation of benign and malignant cystic lesions of the breast

OBJECTIVE

The purpose of this study was to subdivide the types of sonographic findings of benign versus malignant cystic masses and to determine appropriate patient care according to the sonographic findings with pathologic correlation.

METHODS

The sonographic findings of 175 symptomatic cystic breast lesions were pathologically proven and reviewed retrospectively. Cystic lesions were classified as 6 types: simple cysts (type I), clustered cysts (type II), cysts with thin septa (type III), complicated cysts (type IV), cystic masses with a thick wall/septa or nodules (type V), and complex solid and cystic masses (type VI). Sonographic findings were compared with the pathologic results and were evaluated according to the incidence of benign and malignant masses.

RESULTS

All 23 type I, 15 type II, 22 type III, and 35 type IV cases were pathologically proven to be benign. Seven (25.9%) of the 27 type V cases and 33 (62.3%) of the 53 type VI cases were proven to be malignant. We analyzed the shapes and margins of 80 cases of cystic masses with a solid component (types V and VI); 16 (44%) of 36 sonographically circumscribed masses were malignant.

CONCLUSIONS

Because the sonographically detected simple cysts (type I), clustered cysts (type II), and cysts with thin septa (type III) were all benign, annual routine follow-up appears reasonable. Symptomatic complicated cysts (type IV) should be aspirated and appropriately treated according to clinical symptoms. Cystic masses with a solid component (types V and VI) should be examined by biopsy with pathologic confirmation.

Operator dependence of physician-performed whole-breast US: lesion detection and characterization

PURPOSE

To prospectively examine operator dependence of lesion detection, description, and interpretation when experienced breast radiologists perform whole-breast ultrasonography (US).

MATERIALS AND METHODS

Institutional review board approval was obtained for the HIPAA-compliant study. Ten women (aged 19-53 years; mean, 37.4 years; 20 breasts) with numerous known breast lesions consented to participate. Eleven breast radiologists, who passed experience and qualification requirements for a screening breast US trial and consented to participate, scanned both breasts in all participants and documented images of each detected lesion and its size, location, features, palpability, and Breast Imaging Reporting and Data System final assessment. Intraclass correlation coefficients (ICCs) were used to measure agreement on lesion size and location, and kappa statistics were calculated for agreement on features and final assessments compared with consensus.

RESULTS

Eighty-eight unique lesions were identified by at least two investigators (five to 13 lesions per participant). Mean diameter was 6.7 mm (standard error, 0.4; range, 2-22 mm), and eight lesions (9%) were palpable. Of 968 potential detections (88 lesions, 11 investigators), 536 (55%) detections were made. Individual investigators detected between 43 (49%) and 58 (66%) lesions. Larger lesions were more consistently detected: Detection rates were six of 33 lesions (18%) at 3 mm or smaller; 164 of 374 (43.9%) at 3.1-5 mm; 145 of 275 (52.7%) at 5.1-7 mm; 119 of 176 (67.6%) at 7.1-9 mm; 38 of 44 (86%) at 9.1-11 mm; and 64 of 66 (97%) lesions larger than 11 mm (P < .001). ICCs for clockface, distance from nipple, and individual lesion diameter all exceeded 0.7, indicating high reliability. For shape, margins, and final assessments of solid lesions, kappa values were 0.62, 0.67 (substantial agreement), and 0.52 (moderate agreement), respectively. Of 110 detections of consensus cysts 8 mm and smaller, 15 (14%) detections were considered to be of solid lesions by at least one reader.

CONCLUSION

Larger lesions (>11 mm) are most consistently detected, with fewer than half of lesions 5 mm or smaller in mean diameter identified; substantial agreement was found for description of lesion size, location, and key features, and moderate agreement was found for lesion management.

Rapidly growing nodular pseudoangiomatous stromal hyperplasia of the breast in an 18-year-old girl. Case report

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a rare benign proliferation of mesenchymal stromal cells with irregular slit-like formations resembling angiomatous structures. In the majority of cases this lesion is a focal microscopic finding in breast biopsies performed for benign or malignant diseases. It may present in a pure diffuse or nodular form. The exact etiology and pathogenesis of this tumor-like lesion is still unknown, but a proliferative response of myofibroblasts to hormonal stimuli has been postulated. A large 12 x 9 x 3.5 cm rapidly growing nodular form of PASH of the breast in an 18-year-old woman is here described with clinical and histological findings. A possible hormonal etiology was indicated by elevated progesterone (three-fold) and decreased estrogen serum levels. Different diagnostic lesions, such as giant fibroadenoma and low-grade angiosarcoma, are discussed. To the authors' knowledge this is only the fourth case of nodular PASH of the breast reported in the English literature.

Sonographically Depicted Breast Clustered Microcysts: Is Follow-Up Appropriate?

OBJECTIVE

The objective of this study was to evaluate outcomes of lesions prospectively classified on breast sonography as clustered microcysts without a discrete solid component.

SUBJECTS AND METHODS

Over a 4-year interval during which 1,900 consecutive breast sonography examinations were obtained at the University of Maryland, 110 examinations (5.8%) yielded 123 lesions so classified. Sonography was performed by a physician using a linear-array broadband transducer (L7.5-12 or L7-13 MHz). Follow-up of at least 24 months was available for 66 lesions, and 14-gauge core biopsy was performed on another 13 lesions. The median patient age was 48 years (range, 32-71 years), and the median lesion size was 8 mm (range, 5-30 mm).

RESULTS

Of the 79 lesions with acceptable follow-up, all were depicted sonographically, 57 (72%) were seen mammographically, and four (5%) were palpable. Of the 13 lesions biopsied, five (38%) showed apocrine metaplasia; five (38%), fibrocystic changes; two (15%), cysts; and one (8%), a microscopic fibroadenoma and cysts. Of the 66 lesions with 2-year follow-up, 35 (53%) were stable, 15 (23%) had resolved, 12 (18%) decreased, and four (6%) minimally increased at 1 year and were then stable (n = 2) or decreased (n = 2) after 2 subsequent years. Fusion of several small cystic spaces was seen in one (2%) of the lesions followed.

CONCLUSION

Breast clustered microcysts are relatively common, seen in 5.8% of breast sonograms. In our series of 79 lesions with follow-up, none proved malignant: Follow-up on an annual basis appears reasonable for most such lesions. Validation of this approach across multiple centers is needed.

Cystic lesions of the breast: sonographic-pathologic correlation

PURPOSE

To understand the pathologic basis for sonographic features of cystic lesions of the breast and determine appropriate assessment and management recommendations for these lesions based on sonographic appearance.

MATERIALS AND METHODS

From a database of 2,072 image-guided procedures performed from July 1995 through September 2001, 150 cystic lesions were identified. Diagnosis was established with fine-needle aspiration (n = 55), 14-gauge core-needle biopsy (n = 81), or both (n = 14). Excision was performed for all malignant (n = 18) and atypical (n = 2) lesions and for 11 benign lesions, which recurred or enlarged at follow-up. Imaging follow-up was available for 92 of 119 benign lesions. Targeted sonography was performed with high-frequency (10-MHz center frequency) transducers. Imaging and histopathologic, cytologic, and/or microbiologic findings were reviewed. Lesions were categorized as simple cysts, complicated cysts (imperceptible wall, acoustic enhancement, low-level echoes), clustered microcysts, cystic masses with a thick (perceptible) wall and/or thick (> or =0.5 mm) septations, intracystic or mixed cystic and solid masses (at least 50% cystic), or predominantly solid masses with eccentric cystic foci.

RESULTS

Of 150 lesions, 16 were simple cysts aspirated for symptomatic relief. Of 38 lesions characterized as complicated cysts and one cyst with thin septations, none proved malignant, nor did any of 16 lesions characterized as clustered microcysts. Of 23 masses with thick indistinct walls or thick septations, seven proved malignant. Of 18 intracystic or mixed cystic and solid masses, four proved malignant. Of 38 predominantly solid masses with eccentric cystic foci, seven proved malignant.

CONCLUSION

Symptomatic complicated cysts generally warrant aspiration. All clustered microcysts were benign, but further study is required. Cystic lesions with thick indistinct walls and/or thick septations (> or =0.5 mm), intracystic masses, and predominantly solid masses with eccentric cystic foci should be examined at biopsy; 18 of 79 of such complex cystic lesions proved malignant in this series.

Imaging findings in Mondor's disease

Mondor's disease, or acute thrombophlebitis of superficial veins of the breast, occurs rarely, and little information is available in the medical literature on imaging findings in this disease. We present the case of a 59-year-old woman who underwent evaluation of a palpable, painful cord in her left breast associated with discoloration of the overlying skin. Mammography revealed a 10-cm-long linear density in her left breast. Gray-scale sonography showed a noncompressible, hypoechoic, undulating tubular structure in the subcutaneous fat. Color Doppler imaging revealed no flow signal in this structure, although we observed arterial flow signals adjacent to it. We diagnosed Mondor's disease and treated the patient symptomatically; 6-week follow-up examinations demonstrated resolution of the venous thrombosis. The use of sonography, particularly color Doppler imaging, can aid in diagnosing Mondor's disease and in monitoring its resolution.

Electrical impedance spectroscopy of the breast: clinical imaging results in 26 subjects

Electrical impedance spectroscopy (EIS) is a potential, noninvasive technique to image women for breast cancer. Studies have shown characteristic frequency dispersions in the electrical conductivity and permittivity of malignant versus normal tissue. Using a multifrequency EIS system, we imaged the breasts of 26 women. All patients had mammograms ranked using the American College of Radiology (ACR) BIRADS system. Of the 51 individual breasts imaged, 38 were ACR 1 negative, six had ACR 4-5 suspicious lesions, and seven had ACR 2 benign findings such as fibroadenomas or calcifications. A radially translatable circular array of 16 Ag/AgCl electrodes was placed around the breast while the patient lay prone. We applied trigonometric voltage patterns at ten frequencies between 10 and 950 kHz. Anatomically coronal images were reconstructed from this data using nonlinear partial differential equation methods. Typically, ACR 1-rated breasts were interrogated in a single central plane whereas ACR 2-5-rated breasts were imaged in multiple planes covering the region of suspicion. In general, a characteristic homogeneous image emerged for mammographically normal cases while focal inhomogeneities were observed in images from women with malignancies. Using a specific visual criterion, EIS images identified 83% of the ACR 4-5 lesions while 67% were detected using a numerical criterion. Overall, multifrequency electrical impedance imaging appears promising for detecting breast malignancies, but improvements must be made before the method reaches its full potential.

The role of ultrasonography as an adjunct to mammography in the detection of breast cancer. a systematic review

The aim of this review was to summarise the diagnostic performance of ultrasonography as an adjunct to mammography in the detection of breast cancer and to identify clinical indications. A systematic review was performed of all publications in MEDLINE and EMBASE between 1990 and 2000 on the role of ultrasonography as an adjunct to mammography. 22 studies were included, showing a large variety of indications for ultrasonography and variations in the diagnostic performance of mammography and ultrasonography. There were six studies comparing a combined diagnosis of mammography and ultrasonography together with mammography alone, of which three studies had an increased sensitivity at the cost of a lower specificity. The methods of selecting the study population and interpretation of ultrasonography significantly influenced the diagnostic performance of mammography and ultrasonography relative to each other (P=0.003, P=0.03, respectively). Based on the studies reviewed, little evidence-based support was found to confirm the well recognised value of ultrasonography as an adjunct to mammography in the detection of breast cancer in clinical practice. Furthermore, no clinical indications for additional ultrasonography could be defined. The heterogeneity in the diagnostic performance in these studies may be explained by the methods of patient selection and ultrasonography interpretation, as well as by their poor quality.

Overview of breast imaging

In summary, it is an exciting time in breast imaging with many tools being brought to bear on an ever more common problem. The challenge for this decade will be to develop optimal cost-effective strategies to use all the tools now available with minimal discomfort and disfigurement to the patient.