Meta-analysis: Radial Scar and Breast MRI.

BACKGROUND: The implementation of digital breast tomosynthesis has increased the detection of radial scar (RS). Managing this finding may be experienced as a clinical dilemma in daily practice. Breast Contrast-Enhanced MRI (CE-BMR) is a known modality in case of problem-solving tool for mammographic abnormalities. However, the data about AD and CE-BMR are scant. OBJECTIVE: The purpose was to estimate the benefit of CE-BMR in the setting of RS detected mammographically through a systematic review and meta-analysis of the literature. METHODS: A search of MEDLINE and EMBASE databases were conducted in 2022. Based on the PRISMA guidelines, an analysis was performed. The primary endpoint was the correlation between CE-BMR findings and definite outcome for RS (pure RS versus RS associated with atypia or malignancy). RESULTS: Three studies were available. The negative predictive value (NPV) was 100% for each. CONCLUSION: The high NPV could allow for deferral of a biopsy in favor of a short-interval imaging follow-up in the setting of a negative CE-BMR.

Machine learning analysis of breast ultrasound to classify triple negative and HER2+ breast cancer subtypes.

OBJECTIVES: Early diagnosis of triple-negative (TN) and human epidermal growth factor receptor 2 positive (HER2+) breast cancer is important due to its increased risk of micrometastatic spread necessitating early treatment and for guiding targeted therapies. This study aimed to evaluate the diagnostic performance of machine learning (ML) classification of newly diagnosed breast masses into TN versus non-TN (NTN) and HER2+ versus HER2 negative (HER2-) breast cancer, using radiomic features extracted from grayscale ultrasound (US) b-mode images. MATERIALS AND METHODS: A retrospective chart review identified 88 female patients who underwent diagnostic breast US imaging, had confirmation of invasive malignancy on pathology and receptor status determined on immunohistochemistry available. The patients were classified as TN, NTN, HER2+ or HER2- for ground-truth labelling. For image analysis, breast masses were manually segmented by a breast radiologist. Radiomic features were extracted per image and used for predictive modelling. Supervised ML classifiers included: logistic regression, k-nearest neighbour, and Naïve Bayes. Classification performance measures were calculated on an independent (unseen) test set. The area under the receiver operating characteristic curve (AUC), sensitivity (%), and specificity (%) were reported for each classifier. RESULTS: The logistic regression classifier demonstrated the highest AUC: 0.824 (sensitivity: 81.8%, specificity: 74.2%) for the TN sub-group and 0.778 (sensitivity: 71.4%, specificity: 71.6%) for the HER2 sub-group. CONCLUSION: ML classifiers demonstrate high diagnostic accuracy in classifying TN versus NTN and HER2+ versus HER2- breast cancers using US images. Identification of more aggressive breast cancer subtypes early in the diagnostic process could help achieve better prognoses by prioritizing clinical referral and prompting adequate early treatment.

A rare presentation of pregnancy associated primary angiosarcoma of the breasts.

Primary angiosarcoma of the breast is a rare malignancy that is important for radiologists to recognize in young patients because its imaging appearance may mimic benign lesions resulting in advanced stages of disease and overall decreased patient survival. We present a unique case of a bilateral primary angiosarcoma in a pregnant patient in her twenties. She presented with a self-detected, rapidly enlarging, non-tender right breast mass while in her third trimester.

Missed Breast Cancers on MRI in High-Risk Patients: A Retrospective Case-Control Study.

Purpose: To determine if MRI features and molecular subtype influence the detectability of breast cancers on MRI in high-risk patients. Methods and Materials: Breast cancers in a high-risk population of 104 patients were diagnosed following MRI describing a BI-RADS 4-5 lesion. MRI characteristics at the time of diagnosis were compared with previous MRI, where a BI-RADS 1-2-3 lesion was described. Results: There were 77 false-negative MRIs. A total of 51 cancers were overlooked and 26 were misinterpreted. There was no association found between MRI characteristics, the receptor type and the frequency of missed cancers. The main factors for misinterpreted lesions were multiple breast lesions, prior biopsy/surgery and long-term stability. Lesions were mostly overlooked because of their small size and high background parenchymal enhancement. Among missed lesions, 50% of those with plateau kinetics on initial MRI changed for washout kinetics, and 65% of initially progressively enhancing lesions then showed plateau or washout kinetics. There were more basal-like tumours in BRCA1 carriers (50%) than in non-carriers (13%), p = 0.0001, OR = 6.714, 95% CI = [2.058-21.910]. The proportion of missed cancers was lower in BRCA carriers (59%) versus non-carriers (79%), p < 0.05, OR = 2.621, 95% CI = [1.02-6.74]. Conclusions: MRI characteristics or molecular subtype do not influence breast cancer detectability. Lesions in a post-surgical breast should be assessed with caution. Long-term stability does not rule out malignancy and multimodality evaluation is of added value. Lowering the biopsy threshold for lesions with an interval change in kinetics for a type 2 or 3 curve should be considered. There was a higher rate of interval cancers in BRCA 1 patients attributed to lesions more aggressive in nature.

Upgrade rate of percutaneously diagnosed pure flat epithelial atypia: systematic review and meta-analysis of 1,924 lesions.

CONTEXT: Management remains controversial due to the risk of upgrade for malignancy from flat epithelial atypia (FEA). Data about the frequency and malignancy upgrade rates are scant. Namely, observational follow-up is advised by many studies in cases of pure FEA on core biopsy and in the absence of an additional surgical excision. For cases of pure FEA, the American College of Surgeons no longer recommends surgical excision but rather recommends observation with clinical and imaging follow-up. OBJECTIVES: The aim of this study is to perform a systematic review and meta-analysis to calculate the pooled upgrade of pure FEA following core needle biopsies. METHODS: A search of MEDLINE and Embase databases were conducted in December 2020. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A fixed- or random-effects model was utilized. Heterogeneity among studies was estimated by utilizing the I2 statistic and considered high if the I2 was greater than 50%. The random-effects model with the DerSimonian and Laird method was utilized to calculate the pooled upgrade rate and its 95% confidence interval. RESULTS: A total of 1924 pure FEA were analyzed among 59 included studies. The overall pooled upgrade rate to malignancy was 8.8%. The pooled upgrade rate for mammography only was 8.9%. The pooled upgrade rate for ultrasound was 14%. The pooled upgrade rate for mammography and ultrasound combined was 8.8%. The pooled upgrade rate for MRI-only cases was 27.3%. CONCLUSIONS: Although the guidelines for the management of pure FEA are variable, our data support that pure FEA diagnosed at core needle biopsy should undergo surgical excision since the upgrade rate >2%.

Meta-analysis: Architectural distortion and breast MRI.

BACKGROUND: The implementation of digital breast tomosynthesis has increased the detection of architectural distortion (AD). Managing this finding may be experienced as a clinical dilemma in daily practice. Breast Contrast-Enhanced MRI (CE-BMR) is a known modality in case of problem-solving tool for mammographic abnormalities. However, the data about AR and CE-BMR are scant. OBJECTIVE: The purpose was to estimate the benefit of CE-BMR in the setting of architectural distortion detected mammographically through a systematic review and meta-analysis of the literature. METHODS: A search of MEDLINE and EMBASE databases were conducted in 2020. Based on the PRISMA guidelines, an analysis was performed using the chi-square test of independence to determine if there was a significant association between the result of the test (positive or negative) and the participant condition (malignant or non-malignant). RESULTS: Four studies were available. The negative predictive value (NPV) was 98.3% to 100%. The result of the chi-square indicated that there was significant association between the participant test result and the participant condition for the included publications (X(1,175)2= 84.051, p = 0.0001). CONCLUSIONS: The high NPV could allow for deferral of a biopsy in favor of a short-interval imaging follow-up in the setting of a negative CE-BMR.

A rare presentation of tuberculous adenitis mimicking metastatic breast lymphadenopathy.

Tuberculosis (TB) remains in 2022 a significant public health issue as it remains endemic in some areas of the globe, with a high prevalence in underdeveloped countries (Pujani, Khan, Hassan, Jetley, Raina, Breast Dis., 35(3): 195-198, 2015. doi:10.3233/BD-150405. PMID: 26406543). Pulmonary TB is the most common form, but TB can also have extrapulmonary manifestations like tubercular lymphadenopathy. Tuberculous lymphadenitis is the most extrapulmonary tuberculosis. It used to be called scrofula in the past coming from the Latin meaning breeding sow (Kokosali, Lloyd, Dent Update, 33(5): 306-308, 311, 2006. doi:10.12968/denu.2006.33.5.306. PMID: 16841612; Oberhelman, Watchmaker, Phillips, JAMA Dermatol, 155(5): 610, 2019. doi:10.1001/jamadermatol.2018.5651. PMID: 30942835). It is a common cause of peripheral lymphadenitis, seen mostly in the developing countries, but also reemerging among intravenous drugs users and immunocompromised population. Cervical nodes are the most commonly detected nodes in tuberculous lymphadenitis, accounting for 63% of the cases, followed by mediastinal (27%) and axillary nodes (8%) (Ahuja, Ying, Evans, King, Metreweli, Clin Radiol, 50(6): 391-395, 1995. doi:10.1016/s0009-9260(05)83136-8. PMID: 7789023). Tuberculous lymphadenitis affects predominantly the young population and children. There is also a slight female predilection. As to our knowledge, there have not been any reported cases as post-menopausal axillary tuberculous lymphadenitis, and it is the focus of this article.

Flat epithelial atypia: What the radiologist needs to know in 2021.

The World Health Organization defines flat epithelial atypia (FEA), as a "presumably neoplastic intraductal alteration characterized by the replacement of native epithelial cells by a single layer or three to five layers of mildly atypical cells.". In this article, we will review FEA and compare its characteristics and differences with other atypical high-risk breast lesions. In addition, the imaging appearance of FEA will be described. Finally, we will discuss current outcomes and provide an update on its management based on the last recommendations.

Can strain elastography improve the characterization of breast lesions identified during second-look MRI-directed sonographic examination?

PURPOSE: To evaluate strain elastography as a complementary tool for characterization of lesions identified during second-look MRI-directed sonographic examination. METHODS: We reviewed 83 breast lesions evaluated with MRI, secondlook ultrasound (US) and strain elastography in 75 consecutive patients (median age, 56 years). US-guided biopsies were performed in all cases. RESULTS: After histopathological examination, 44 lesions were benign, 38 were malignant and 1 was high-risk. At MRI, the mean size of the lesions was 12 mm. Forty lesions (48.2%) appeared as masses, 30 (36.1%) as "non-masses" and 13 (15.7%) as "foci." At second-look US examination, 56 (67.5%) appeared as masses (mean size, 7 mm) and 27 (32.5%) as non-masses (mean size, 14 mm). At strain elastography, among the 39 malignant/high risk lesions, 5 (12.8%) had a score of 4 or 5, whereas 16 (41%) had a score of 1 and 2 (false negative). Among the 44 benign lesions, 36 (82%) had a score of 1 or 2, whereas none had a score of 5. Sensitivity and specificity of strain elastography in the diagnosis of breast cancer were 58% and 81%, respectively. CONCLUSION: The addition of strain elastography offers no benefit in the characterization of lesions identified on second-look US after breast MRI.(E1, 3).

Sonoelastography of retroareolar carcinomas.

PURPOSE: To review the sonographic and elastographic features of retroareolar carcinomas. MATERIALS: Institutional review board approval was obtained. Among 967 sonographically guided biopsies (2013-2014) (14-gauge cores), 53 yielded the diagnosis of retroareolar carcinoma (located less than 2cm from the nipple on mammograms). Out of these 53 lesions, 30 were assessed additionally with strain elastography prior to the biopsy in addition to conventional sonographic analysis. Imaging features were analyzed in consensus by two radiologists. Elasticity score was evaluated by the score defined by Itoh (Tsukuba score). Descriptive analysis was performed. RESULTS: A total of 30 lesions were included (30 patients; mean age, 66.03 (±12.88)). The mean size of the lesions at diagnosis was 23.97mm (±13.64). Sonographically, most of lesions appeared as hypoechoic masses (96.5%, 28/29) displaying an irregular shape (75.9%, 22/29), non parallel orientation (58.6%, 17/29), non circumscribed margins (86.2%, 25/29), posterior attenuation (93.3%, 28/29). Among the 30 lesions, 3.3% (1/30) of lesions appeared as an attenuation and distortion without discrete mass. Most of the lesions were categorized as BI-RADS category 5 (76.7%, 23/30). Approximately half of lesions (53.3%, 16/30) appeared as firm and larger than 2D mode with strain elastography according to the Tsukuba score. CONCLUSION: Retroareolar carcinoma displayed malignant features at US and elastographic examination. In our study population, the addition of elastography to breast US in this location did not improve diagnostic accuracy.

Features from Computerized Texture Analysis of Breast Cancers at Pretreatment MR Imaging Are Associated with Response to Neoadjuvant Chemotherapy.

Purpose To evaluate whether features from texture analysis of breast cancers were associated with pathologic complete response (pCR) after neoadjuvant chemotherapy and to explore the association between texture features and tumor subtypes at pretreatment magnetic resonance (MR) imaging. Materials and Methods Institutional review board approval was obtained. This retrospective study included 85 patients with 85 breast cancers who underwent breast MR imaging before neoadjuvant chemotherapy between April 10, 2008, and March 12, 2015. Two-dimensional texture analysis was performed by using software at T2-weighted MR imaging and contrast material-enhanced T1-weighted MR imaging. Quantitative parameters were compared between patients with pCR and those with non-pCR and between patients with triple-negative breast cancer and those with non-triple-negative cancer. Multiple logistic regression analysis was used to determine independent parameters. Results Eighteen tumors (22%) were triple-negative breast cancers. pCR was achieved in 30 of the 85 tumors (35%). At univariate analysis, mean pixel intensity with spatial scaling factor (SSF) of 2 and 4 on T2-weighted images and kurtosis on contrast-enhanced T1-weighted images showed a significant difference between triple-negative breast cancer and non-triple-negative breast cancer (P = .009, .003, and .001, respectively). Kurtosis (SSF, 2) on T2-weighted images showed a significant difference between pCR and non-pCR (P = .015). At multiple logistic regression, kurtosis on T2-weighted images was independently associated with pCR in non-triple-negative breast cancer (P = .033). A multivariate model incorporating T2-weighted and contrast-enhanced T1-weighted kurtosis showed good performance for the identification of triple-negative breast cancer (area under the receiver operating characteristic curve, 0.834). Conclusion At pretreatment MR imaging, kurtosis appears to be associated with pCR to neoadjuvant chemotherapy in non-triple-negative breast cancer and may be a promising biomarker for the identification of triple-negative breast cancer. © RSNA, 2017.

The Positive Outcome of MRI-Guided Vacuum Assisted Core Needle Breast Biopsies Is Not Influenced by a Prior Negative Targeted Second-Look Ultrasound.

PURPOSE: The study sought to investigate the outcome of breast magnetic resonance-guided biopsies as a function of the indication for magnetic resonance imaging (MRI), the MRI features of the lesions, and the performance or not of a targeted second-look ultrasound (SLUS) prior breast MRI-guided biopsy. METHODS: We identified 158 women with MRI-detected breast lesions scheduled for MRI-guided biopsy (2007-2013). Patient demographics, performance of targeted SLUS, imaging characteristics, and subsequent pathology results were reviewed. RESULTS: Three biopsies were deferred, and 155 lesions were biopsied under MRI guidance (155 women; median age 55.14 years; range 27-80 years). Ninety-eight women underwent a SLUS prior to the MRI-guided biopsy (63%). Of the 155 biopsied lesions, 23 (15%) were malignant, 106 (68%) were benign, and 26 (17%) were high risk. Four of 15 surgically excised high-risk lesions were upgraded to malignancy (27%). Most of the biopsied lesions corresponded to non-mass-like enhancement (81%, 126 of 155) and most of the biopsies (52%, 81 of 155) were performed in a screening context. No demographic or MRI features were associated with malignancy. No differences were noted between the 2 subgroups (prior SLUS vs no prior SLUS) except for the presence of a synchronous carcinoma associated with a likelihood of targeted SLUS before MRI-guided biopsy (P = .001). CONCLUSION: A negative SLUS does not influence the pathology outcome of a suspicious lesion biopsied under MR guidance.

Imaging features and conspicuity of invasive lobular carcinomas on digital breast tomosynthesis.

OBJECTIVE: To review the imaging features of invasive lobular carcinoma (ILC) seen on digital breast tomosynthesis (DBT) in comparison with invasive ductal carcinoma (IDC), and to evaluate whether DBT could improve conspicuity and tumour size assessment of ILC in comparison with digital mammography (DM). METHODS: Institutional review board with waiver of informed consent was obtained for this retrospective study. Patients with ILC or IDC who underwent DBT and DM at the time of diagnosis were included. DM and DBT images were reviewed in consensus by two breast radiologists in order to assess imaging features, conspicuity and maximum tumour diameter of ILC and IDC. Pathology on the surgical specimen was considered the standard of reference for assessment of tumour size. RESULTS: 43 patients (20 patients with ILC and 23 patients with IDC) were included. On DBT, compared with IDC, ILC presented less frequently as masses (40% vs 78%) (p = 0.01) and more frequently as isolated distortion (20% vs 0%) (p = 0.03). ILC presented more often as asymmetries (60%) than masses (20%) on DM (p = 0.02) but not on DBT (35% vs 40%; p = 1.00). Conspicuity of ILC was significantly higher on DBT than on DM (p = 0.002), while the difference between the two techniques was not significant for IDC (p = 0.2). Regarding ILC, concordance in tumour size measurement between DBT and pathology was fair (intraclass correlation coefficient = 0.24). CONCLUSION: ILC rarely presented as dense masses but frequently demonstrated architectural distortion on DBT. DBT increased lesion conspicuity but failed to accurately assess tumour size of ILC. Advances in knowledge: (1) This study describes specific features of ILC on DBT. (2) It shows that DBT can improve conspicuity of ILC.

Sonographic Appearance of Lesions Diagnosed as Lobular Neoplasia at Sonographically Guided Biopsies.

OBJECTIVE: The objective of our study was to review the sonographic features of breast lesions yielding lobular neoplasia (LN) at sonographically guided biopsy, evaluate the surgical pathology outcome of these lesions, and determine if imaging findings or clinical features can be used to predict an upgrade to malignancy. MATERIALS AND METHODS: Of the 8205 sonographically guided breast biopsies (14-gauge cores) performed from 2007 through 2014, 22 yielded a diagnosis of LN, which means that LN was the most severe pathologic lesion. Imaging features were analyzed in consensus by two radiologists. Correlation of biopsy findings with definitive pathologic results was performed when available. RESULTS: Twenty-two LN lesions (20 patients [mean age ± SD, 52.05 ± 13.66 years]) were diagnosed at biopsy. Of the LN lesions that were seen on mammography (6/22, 27.3%), most lesions appeared as masses (3/6, 50%). On sonography, LN lesions (mean size, 8.10 mm) appeared as masses (15/22, 68.2%) with oval shape (10/15, 66.7%), well-circumscribed or microlobulated margins (11/15, 73.3%), hypoechoic echotexture (10/15, 66.7%), posterior enhancement (73.3%, 11/15), and parallel orientation (8/15, 53.3%). Most of the masses were categorized as BI-RADS category 4 (21/22, 95.5%). Seven lesions (7/22, 31.8%) appeared as areas of shadowing or distortion without discrete masses. Twenty (20/22, 90.9%) lesions were excised surgically, and pathology results led to an upgrade in five lesions (5/20, 25% [one nonmass lesion and four masses]). Neither mammographic nor sonographic features were associated with malignant outcome (p > 0.05). CONCLUSION: LN diagnosed at sonographically guided 14-gauge core needle biopsy does not show any specific features according to the BI-RADS lexicon and is associated with a 25% underestimation rate. No clinical or imaging characteristic is predictive of malignancy.

Imaging Features Associated With Posttraumatic Breast Neuromas.

OBJECTIVE: The aim of this study is to review the clinical and imaging features of patients with a histopathologic diagnosis of posttraumatic breast neuromas. MATERIALS AND METHODS: We report eight biopsy-proven posttraumatic neuromas in six patients with a history of breast surgery. Mammographic, sonographic, and breast MRI examinations were reviewed according to the BI-RADS lexicon. In addition, the tail sign, a specific sign known to be associated with neuromas in other parts of the body, was assessed. RESULTS: Mammographic, MRI, and sonographic examinations were performed in three, four and all six patients, respectively. The neuromas were occult on the three mammograms performed but all of them were identified on ultrasound as hypoechoic masses with parallel orientation; seven of the eight neuromas (87.5%) had an oval shape with circumscribed margins. Strain elastography performed for two patients (three neuromas) showed benign features (benign elasticity scores and fat-to-lesion ratio). Half of the masses showed a tail sign (focal thickening of the nerve adjacent to posttraumatic neuroma, similar to the dural tail sign). Of five lesions investigated by MRI, two were occult on MRI. The remaining three were visible as isointense foci on T1-weighted images, with a benign type 1 enhancement curve. CONCLUSION: In patients who underwent breast surgery, a mass with benign features raises the possibility of a neuroma. Although the tail sign was present in half of the posttraumatic neuromas, imaging-guided biopsy remains the standard of care.

Differentiation of Fibroadenomas and Pure Mucinous Carcinomas on Dynamic Contrast-Enhanced MRI of the Breast Using Volume Segmentation for Kinetic Analysis: A Feasibility Study.

OBJECTIVE: The objective of this study was to retrospectively evaluate the diagnostic performance of volume-based kinetic analysis in dynamic contrast-enhanced MRI (DCE-MRI) of the breast for the differentiation of fibroadenomas (FAs) with high T2 signal intensity from pure mucinous carcinomas (PMCs). MATERIALS AND METHODS: A review of records from 2007 to 2013 that were stored in the pathology department database at our institution identified nine patients with PMCs (defined as tumor cells with a mucinous component ≥ 90%) who underwent preoperative breast MRI. The PMCs were compared with 15 biopsy-proven FAs from 13 patients. Characteristics noted on DCE-MRI were evaluated using computer-assisted diagnosis software. For each mass, the proportion of progressive enhancement in the lesion at the delayed phase was quantified. Both groups of masses were compared using a Wilcoxon signed rank test. A ROC curve was used to define an appropriate cutoff point. RESULTS: The median rate of progressive enhancement was 100% (range, 99-100%) for FAs and 97% (range, 87-99%) for PMCs (p = 0.0326). The AUC of the kinetic curve for progressive enhancement was 0.7519 (95% CI, 0.5258-0.9407). A more appropriate cutoff value to maximize sensitivity and specificity was 98.5%. With this cutoff, sensitivity was 66.7% (95% CI, 11.1-100%) and specificity was 80% (95% CI, 39.6-99.8%) for the diagnosis of PMCs. CONCLUSION: Volume-based kinetic analysis may aid in differentiating FAs from PMCs on DCE-MRI studies of the breast.

Retroareolar Carcinomas in Breast Ultrasound: Pearls and Pitfalls.

Breast Ultrasound (US) is an important tool for both screening and diagnostic examinations. Although breast US has benefitted from significant recent technical improvements, its use for the retroareolar region is known to be more challenging than for other locations. The retroareolar location was defined by Giess et al. in 1998 as the region where any lesion is situated at less than two cm from the nipple and/or involves the nipple-areolar complex on mammogram. Understanding of the complex anatomy and physiology of the nipple-areolar region is important to avoid misinterpretation and misdiagnosis. The ability for the breast imager to manage difficulties related to the retroareolar area is paramount by adjusting settings (compounding, frequency, Doppler) and utilizing specific manoeuvers. Cases illustrating difficulties encountered in diagnosis of retroareolar carcinomas are presented.

Value of pre-operative breast MRI for the size assessment of ductal carcinoma in situ.

OBJECTIVE: To retrospectively evaluate the accuracy of pre-operative breast MRI and mammography in determining the size of ductal carcinoma in situ (DCIS) compared with the histopathological results. METHODS: 79 patients [mean age: 56.5 (standard deviation 10.2) years] with pathologically proven DCIS (79 lesions) obtained a bilateral mammogram and a pre-operative contrast-enhanced MRI. The accuracy of MRI and mammography to detect tumour size were estimated and compared, using histopathological size as the gold standard, on the subjects with measurements with both modalities (n = 60). RESULTS: MRI detected 67 (85%) lesions, mammography detected 72 (91%) and both modalities detected 60 (76%). Median DCIS size detected by mammography vs MRI was smaller (1.55 vs 1.65 cm). Out of these 60 cases, compared with the histopathological size, the accuracy of MRI and mammography was 0.66 and 0.56, respectively (p = 0.045). MRI showed better accuracy than mammography for younger patients (age ≤ 50 years, p = 0.003). For tumour nuclear grade, there was a statistically significant difference for the intermediate level, with higher accuracy for MRI (p = 0.03). CONCLUSION: MRI was more accurate than mammography in DCIS size assessment when visible, particularly in lesions of intermediate grade and in patients less than 50 years of age. ADVANCES IN KNOWLEDGE: Breast MRI may help in management of DCIS of intermediate grade and in females less than 50 years of age.

Diagnostic Performance of MR-guided Vacuum-Assisted Breast Biopsy: 8 Years of Experience.

Breast magnetic resonance imaging (MRI) has demonstrated increased sensitivity over conventional imaging in identifying and characterizing in situ and invasive, multifocal, and multicentric disease. A histologic diagnosis is required for any enhancing lesion displaying suspicious features, especially in the presence of lower and often variable reported specificity values. Breast MRI findings occult on mammography and ultrasound should undergo an MR-guided biopsy. We retrospectively evaluate our 8 years' experience with this procedure. Our study included 259 lesions in 255 consecutive patients referred for MR-guided breast biopsy. MRI screening of women at a high risk for developing breast cancer accounted for 84 lesions, 54 lesions were detected on MRI staging for multifocal and multicentric disease, and 115 were incidental findings or lesions that presented diagnosis related issues on conventional imaging. Six procedures were cancelled due to lack of visualization. MR-guided breast biopsy was performed for 100 mass and 153 nonmass enhancements. Pathology results were classified into benign (113 lesions), high risk (47 lesions), and malignant (40 ductal carcinoma in situ, 38 invasive ductal carcinoma, 15 invasive lobular carcinoma). Subsequent surgery for high risk and malignant findings revealed an underestimation rate of 34% (16/47) for high risk lesions and of 7.5% for ductal carcinoma in situ (3/40). The overall positive predictive value (PPV) was calculated at 43.1% (33.3% for high-risk women, 70.3% for cancer staging, and 37.4% for incidental/undetermined lesions). The PPV was higher for mass (57%) versus nonmass enhancements (34%). MR-guided breast biopsy proved to be a reliable procedure for the diagnosis and management of occult breast MRI findings, or lesions that preclude biopsy under conventional guidance. The PPV displayed significant variation between patient subgroups, correlating higher values with a higher associated breast cancer prevalence.