Digital breast tomosynthesis as an adjunct to digital mammography for detecting and characterising invasive lobular cancers: a multi-reader study.

AIM: To examine the interpretive performance of digital breast tomosynthesis (DBT) as an adjunct to digital mammography (DM) compared to DM alone in a series of invasive lobular carcinomas (ILCs) and to assess whether DBT can be used to characterise ILC. MATERIALS AND METHODS: A retrospective, multi-reader study was conducted of 83 mammographic examinations of women with 107 newly diagnosed ILCs ascertained at histology. Consenting women underwent both DM and DBT acquisitions. Twelve radiologists, with varying mammography experience, interpreted DM images alone, reporting lesion location, mammographic features, and malignancy probability using the Breast Imaging-Reporting and Data System (BI-RADS) categories 1-5; they then reviewed DBT images in addition to DM, and reported the same parameters. Statistical analyses compared sensitivity, false-positive rates (FPR), and interpretive performance using the receiver operating characteristics (ROC) curve and the area under the curve (AUC), for reading with DM versus DM plus DBT. RESULTS: Multi-reader pooled ROC analysis for DM plus DBT yielded AUC=0.89 (95% confidence interval [CI]: 0.88-0.91), which was significantly higher (p<0.0001) than DM alone with AUC=0.84 (95% CI: 0.82-0.86). DBT plus DM significantly increased pooled sensitivity (85%) compared to DM alone (70%; p<0.0001). FPR did not vary significantly with the addition of DBT to DM. Interpreting with DBT (compared to DM alone) increased the correct identification of ILCs depicted as architectural distortions (84% versus 65%, respectively) or as masses (89% versus 70%), increasing interpretive performance for both experienced and less-experienced readers; larger gains in AUC were shown for less-experienced radiologists. Multifocal and/or multicentric and bilateral disease was more frequently identified on DM with DBT. CONCLUSION: Adding DBT to DM significantly improved the accuracy of mammographic interpretation for ILCs and contributed to characterising disease extent.

The wide spectrum of hyperechoic lesions of the breast.

Although breast lesions are commonly detected because of their hypoechogenicity, some lesions may present with hyperechogenicity due to their histological components. Hyperechogenicity has been shown to be highly predictive of benignity; however, hyperechoic lesions can occasionally be malignant. This article reviews hyperechoic lesions of the breast, describes the underlying histological causes associated with hyperechogenicity, and the sonographic features useful for the differential diagnosis between benign and malignant hyperechoic lesions.

An unusual breast lesion: the ultrasonographic, mammographic, MRI and nuclear medicine findings of mammary hibernoma.

We report the case of a 42-year-old woman being treated for an ovarian cancer who was diagnosed at the age of 40. A CT-positron emission tomography (PET) scan performed as follow-up documented abnormal uptake in the right breast. Mammograms were negative for malignancy, while a focal hyperechoic lesion was observed on ultrasonography in the same breast. Thus, she was referred to our institution for breast MRI, which showed a focal area of enhancement with atypical features. Percutaneous biopsy was performed, and a mammary hibernoma was diagnosed. Radiological and pathological correlation was provided. To our knowledge, this is the only report that describes the features of this rare tumour on four different imaging modalities (mammography, ultrasonography, MRI and CT-PET).

Rare breast neoplasms: is there any peculiar feature on magnetic resonance mammography?

PURPOSE: The purpose of this study is to describe the semiological features of rare breast neoplasms at magnetic resonance mammography (MRM). MATERIALS AND METHODS: Out of 468 MRMs of patients with a histological diagnosis of breast malignancy, 27 (5.7%) cases of rare breast neoplasms, confirmed by definitive histological analysis on surgical specimens, were selected: four (0.9%) intracystic papillary neoplasms, four (0.9%) intraductal papillary neoplasms, five (1.0%) invasive papillary neoplasms, two (0.4%) medullary carcinomas, seven (1.5%) mucinous carcinomas, three (0.6%) tubular carcinomas, one (0.2%) tubulo-lobular carcinoma and one (0.2%) desmoid tumour. Two radiologists evaluated the MRM images according to Fischer criteria and indicated a level of diagnostic suspicion. In particular, MRM lesion morphology and enhancement characteristics were analysed. RESULTS: No semiologic features of malignancy or peculiar appearances indicating rare breast neoplasm were identified. On the contrary, MRM appearance was nonspecific and often suggestive of probably benign (Breast Imaging Reporting and Data System-BI-RADS 3) (40%) or benign lesions (BI-RADS 2) (7.5%), or lesions were undetectable at MRM (BI-RADS 1) (7.5%). CONCLUSIONS: Frequently, rare breast neoplasms show low suspicious morphologic and kinetic patterns at MRM, and they are often classified as indeterminate lesions. This is probably due to their high grade of differentiation and their histological features.

Role of ultrasound and sonographically guided core biopsy in the diagnostic evaluation of ductal carcinoma in situ (DCIS) of the breast.

PURPOSE: The aim of this study was to evaluate the role of ultrasound (US)-guided core biopsy in the diagnosis of ductal carcinoma in situ (DCIS) and to correlate the histological results on percutaneous biopsy and surgical excision. MATERIALS AND METHODS: Out of 2,423 consecutive core biopsies performed under US guidance, we evaluated 65 lesions with a histological diagnosis of DCIS. All patients underwent mammography, high-frequency broadband US and percutaneous breast biopsy with a 14-gauge needle and a mean number of five samples (range 4-7 passes). Surgical excision was performed in all cases, and the histological results on the surgical specimen were correlated with those on core biopsy samples. The sonographic features of DCIS lesions were described, comparing pure DCIS (those confirmed by definitive histology) and DCIS with invasive component at surgical excision. RESULTS: Twenty-seven out of 65 DCIS at core biopsy were found to have an invasive or microinvasive component at surgical excision, leading to rate of histological underestimation of core biopsy of 41.5%. The most frequent sonographic appearances were: (a) mass without microcalcifications (47.4% of pure DCIS, 63% of DCIS with invasive component); (b) mass with microcalcifications (23.7% of pure DCIS, 22% of DCIS with invasive component); (c) isolated microcalcifications (10.5% of pure DCIS); (d) ductal abnormalities (18.4% of pure DCIS, 15% of DCIS with invasive component). CONCLUSIONS: Due to the high underestimation rate of core biopsy, caution is mandatory in the case of DCIS diagnosis on core biopsy. Although some histological features (such as stromal fibrosis, periductal inflammatory infiltrate, high nuclear grade) can suggest the presence of an invasive component, the sonographic appearance of DCIS cannot be used to predict the cases that are underestimated on US-guided core biopsy. Nevertheless, a sonographically detectable solid component, either inside dilatated ducts or associated with microcalcifications, and a size greater than 20 mm are frequently associated with the presence of an invasive component.

Stereotactic vacuum-assisted breast biopsy: results, follow-up and correlation with radiological suspicion.

PURPOSE: The purpose of this study was to assess the accuracy and clinical usefulness of stereotactic vacuum-assisted biopsy (VAB) for diagnosing suspicious, nonpalpable, only mammographically detectable breast lesions. MATERIALS AND METHODS: We retrospectively evaluated the results of percutaneous stereotactic VAB with 11-gauge needles performed over a period of 34 months on 228 nonpalpable suspicious breast lesions detectable on mammography only [Breast Imaging Reporting and Data System (BI-RADS) 3: 25.9%; BI-RADS 4: 67.1%; BI-RADS 5: 7%]. The imaging histological concordance was ascertained for each lesion. In cases of discordance, repeat biopsy or surgical excision were recommended; in cases of benign lesions, we urged a follow-up of at least 6 months and for borderline and malignant lesions a surgical excision. We also evaluated concordance between VAB results and subsequent examinations (surgical excision or followup). RESULTS: VAB demonstrated 123 (54%) benign lesions (with six cases of imaging-histological discordance), 26 (11.4%) borderline lesions and 79 (34.6%) malignant lesions. We obtained a suitable post-VAB mammographic or histological evaluation for 78 benign lesions, 17 borderline lesions and 76 malignant lesions, with one (1.3%) false negative (FN) case, two (11.8%) underestimations of borderline lesions, 14 (18.4%) underestimations of malignant lesions and no (0%) false positive cases. We did not observe any postbiopsy complications or scars. CONCLUSIONS: Percutaneous histological VAB with an 11-gauge needle proved to be, as reported in previous studies, a reliable method for diagnosing nonpalpable, mammographically detectable only breast lesions, with an underestimation rate lower than core biopsy and a FN rate similar to that of surgical biopsy, without any significant complications.

Ductal carcinoma in situ: is there a role for MRI?

The purpose of our study is to report personal experience about 28 cases of Ductal Carcinoma In Situ (DCIS) studied with Magnetic Resonance Imaging (MRI). From September 1995 to December 2001, 28 women affected by DCIS lesions underwent contrast enhanced MRI. All patients were submitted previously to mammographic examination. The results of histopathological examination included: 19 DCIS and 9 DCIS with associated microinvasive component or microfoci of invasive ductal carcinoma (IDC). MRI was performed with a 1 T system. A three dimensional fast low-angle shot (FLASH) pulse sequence was used, with a repetition time (TR) of 14 ms, an echo time (TE) of 7 ms and a flip angle of 25 degrees. We evaluated the morphologic features of the enhancement, the enhancement rate and the signal time intensity curve. On MRI 26 out of 28 (92.85%) DCIS lesions showed contrast uptake. 17 out of 19 pure DCIS lesions demonstrated contrast enhancement: 5 showed a low, 7 indeterminate and 5 a strong enhancement. Morphologically, the enhancing lesion was focal in 9, segmental in 5 and linear branching in 3. Wash out was found in 5 cases, plateau curve in 9 and Type I curve in 3. There were 5 cases of multifocality. All DCIS with associated microinvasion demonstrated contrast enhancement: 2 out of 9 cases showed a low enhancement, 4 out of 9 showed an indeterminate enhancement and 3 out of 9 showed a strong enhancement. Morphologically the enhancing lesion was focal in 3 out of 9, segmental in 5 and linear branching in 1. The wash out was demonstrated in 4 cases out of 9, plateau curve in 4 and Type I curve in 1. There were 3 cases of multifocality. In conclusion, MR imaging sensitivity for DCIS detection is lower than that achieved for invasive breast cancer; however, contrast enhanced MR imaging can depict mammographically occult foci of DCIS. The MR imaging technique is of complementary value in better description of tumor size and in additional malignant lesions detection.

[Application of a computer-aided detection (CAD) system to digitalized mammograms for identifying microcalcifications]. / Applicazione di un sistema di Computer Aided Detection (CAD) a mammografie digitalizzate nell-individuazione di microcalcificazioni.

PURPOSE: It is estimated that during mammographic screening programs radiologists fail to detect approximately 25% of breast cancers visible on retrospective review; this percentage rises to 50% if minimal signs are considered. Independent double reading is now strongly recommended as it allows to reduce the rate of false negative examinations by 5-15%. Recent technological progress has allowed to develop a number of computer-aided detection (CAD) systems. The aim of CAD is to help radiologists interpret lesions by serving as a second reader. In this study the authors developed and applied a CAD system to measure its ability to microcalcifications detect and compare its performance with that of a human observer. MATERIAL AND METHODS: The study was performed as part of the CALMA (computer-aided library for mammography) project of the Pisa section of the National Institute of Nuclear Physics. The aim of this project is to set up a large database of digital mammograms and to develop a CAD system. Our study series consisted of 802 mammograms - corresponding to 213 patients - digitalized between March and June 2000. We performed traditional mammography and then digitalized the mammograms using a CCD linear scanner (pixel size of 85 x 85 microm2, 12 bits). The images were evaluated by two radiologists with similar experience and then by the CAD system. This CAD system searches for microcalcifications by using ad hoc algorithms and an artificial neural network (Sanger type). RESULTS: The number of clusters in our database was 141 corresponding to 140 images; 692 images were non pathological. The CAD system identified a variable number of clusters depending on the threshold values. The threshold value is a number over which the probability of finding a lesion is highest. With thresholds of 0.13 and 0.14 the CAD system identified 140/141 clusters (99.3%); with a threshold of 0.15 it identified 139/141 clusters (98.6%); with a threshold of 0.16, 137/141 (97.2%); with a threshold of 0.18, 133/141 (94.3%); with thresholds of 0.18 and 0.20, 130/141 (92.2%). With threshold values of 0.13, 0.14, 0.15, 0.16 and 0.17 the system's sensitivity was greater than 82%, whereas with values of 0.18 and 0.20 it was greater than 80%. The number of false positive region of interest (ROI) / image was greater with low threshold values: in particular, thresholds of 0.13 and 0.14 yielded 16 false positives /image, thresholds of 0.15 and 0.16 yielded 9 and 7 false positives/image, and both 0.18 and 0.20 only 5/image. DISCUSSION: ROC curve shows how the use of high threshold values determined a very high specificity despite very low sensitivity rates. Conversely, low threshold values allowed to have a high sensitivity and a very low specificity. The best performance of our CAD system was obtained with threshold values at 0.15 and 0.16. In fact these thresholds resulted in a high sensitivity (greater than 82%) with an acceptable number of false positives/image, 9 and 7/image, respectively. It is not yet known how radiologists can deal with large numbers of false positives in screening programmes but in our opinion the most important feature of a good CAD system is a high sensitivity. CONCLUSIONS: In the near future the use of CAD systems will be widespread and easier to apply to everyday practice above all in centers where digital mammography is performed. Mammograms could be directly shown to radiologists after the CAD system has selected the ROI and analysed the images. Thanks to its high sensitivity and despite its low specificity CAD represents a concrete aid for radiologists.