Abbreviated Breast MRI for Supplemental Screening in Patients With Dense Breasts: Comparison of Baseline Versus Subsequent-Round Examinations.

Background: Abbreviated breast MRI (AB-MR) achieves a higher cancer detection rate (CDR) versus digital breast tomosynthesis when applied for baseline (i.e. first-round) supplemental screening in individuals with dense breasts. Limited literature has evaluated subsequent (i.e., sequential) AB-MR screening rounds. Objectives: This study aimed to compare outcomes between baseline and subsequent rounds of screening AB-MR in individuals with dense breasts at otherwise average risk of breast cancer. Methods: This retrospective study included patients with dense breasts and at otherwise average breast-cancer risk who underwent AB-MR for supplemental screening between December 20, 2016 and May 10, 2023. Clinical interpretations and results of recommended biopsies for AB-MR examinations were extracted from the EMR. Baseline and subsequent-round AB-MR examinations were compared. Results: The final sample included 2585 AB-MR examinations (2007 baseline, 578 subsequent-round) performed for supplemental screening in 2007 women (mean age, 57.1 years) with dense breasts. Among baseline examinations, 1658 (82.6%) were assessed as BI-RADS category 1 or 2, 171 (8.5%) as category 3, and 178 (8.9%) as category 4 or 5. Among subsequent-round examinations, 533 (92.2%) were assessed as BI-RADS category 1 or 2, 20 (3.5%) as category 3, and 25 (4.3%) as category 4 or 5 (p<.001). Abnormal interpretation rate (AIR) was 17.4% (349/2007) among baseline examinations, versus 7.8% (45/578) among subsequent-round examinations (p<.001). Among baseline examinations, PPV2 was 21.3% (38/178), PPV3 was 26.6% (38/143), and CDR was 18.9 per 1000 (38/2007). Among subsequent-round examinations PPV2 was 28.0% (7/25) (p=.45), PPV3 was 29.2% (7/24) (p=.81), and CDR was 12.1 per 1000 (7/578) (p=.37). All 45 cancers diagnosed by baseline or subsequent-round AB-MR were stage 0 or 1. Seven cancers diagnosed by subsequent-round AB-MR had a mean interval since prior AB-MR of 872 days, size of 0.3-1.2 cm, and node-negative status at surgical axillary evaluation. Conclusion: Subsequent rounds of AB-MR screening in individuals with dense breasts had lower AIR compared to baseline examinations while maintaining high CDR. All cancers detected by subsequent-round examinations were early-stage node-negative cancers. Clinical Impact: The findings support sequential AB-MR for supplemental screening in individuals with dense breasts. Further investigations are warranted to optimize the screening interval.

Management Strategies for Patients Presenting With Symptomatic Lymphadenopathy and Breast Edema After Recent COVID-19 Vaccination.

Ipsilateral axillary lymphadenopathy is a well-documented finding associated with COVID-19 vaccination. Varying guidelines have been published for the management of asymptomatic patients who have a history of recent vaccination and present with incidental lymphadenopathy at screening mammography. Some experts recommend follow-up imaging, and others suggest that clinical management, rather than repeat imaging or biopsy, is appropriate. Symptomatic patients with lymphadenopathy and/or additional abnormal imaging findings should be treated differently depending on risk factors and clinical scenarios. Although ipsilateral lymphadenopathy is well documented, ipsilateral breast edema after COVID-19 vaccination has been rarely reported. The combination of ipsilateral lymphadenopathy and diffuse breast edema after COVID-19 vaccination presents a clinical management challenge because edema can obscure underlying abnormalities at imaging. For symptomatic patients with lymphadenopathy and associated breast parenchymal abnormality, prompt action is appropriate, including diagnostic evaluation and consideration of tissue sampling. This approach may prevent delays in diagnosis and treatment of patients with malignancy masked by symptoms from the vaccination.

Management of Unilateral Axillary Lymphadenopathy Detected on Breast MRI in the Era of COVID-19 Vaccination.

Early clinical experience with COVID-19 vaccination suggests that approved COVID-19 vaccines cause a notably higher incidence of axillary lymphadenopathy on breast MRI compared with other vaccines. Guidelines are needed to appropriately manage unilateral axillary lymphadenopathy detected by MRI in the era of COVID-19 vaccination and to avoid biopsies of benign reactive nodes. This article examines the available data on vaccine-related lymphadenopathy and offers a basic strategy for assessing axillary lymphadenopathy on MRI and guiding management. At our institution, we are adding questions regarding the date(s) and laterality of administration of COVID-19 vaccination to the intake form given to patients before all breast imaging examinations. We consider MRI-detected isolated unilateral axillary lymphadenopathy ipsilateral to the vaccination arm to most likely be related to the COVID-19 vaccine if it develops within 4 weeks of administration of either dose. In these cases, we assess the lymphadenopathy as BI-RADS 3 and recommend that follow-up ultrasound be performed within 6-8 weeks after administration of the second dose. These guidelines may be refined as we acquire further data on the expected time course of axillary lymphadenopathy after COVID-19 vaccination. Until that time, this management pathway will help avoid unnecessary biopsies of benign vaccine-related reactive lymphadenopathy.

Breast MRI: False-Negative Results and Missed Opportunities.

Breast MRI is the most sensitive modality for the detection of breast cancer. However, false-negative cases may occur, in which the cancer is not visualized at MRI and is instead diagnosed with another imaging modality. The authors describe the causes of false-negative breast MRI results, which can be categorized broadly as secondary to perceptual errors or cognitive errors, or nonvisualization secondary to nonenhancement of the tumor. Tips and strategies to avoid these errors are discussed. Perceptual errors occur when an abnormality is not prospectively identified, yet the examination is technically adequate. Careful development of thorough search patterns is critical to avoid these errors. Cognitive errors occur when an abnormality is identified but misinterpreted or mischaracterized as benign. The radiologist may avoid these errors by utilizing all available prior examinations for comparison, viewing images in all planes to better assess the margins and shapes of abnormalities, and appropriately integrating all available information from the contrast-enhanced, T2-weighted, and T1-weighted images as well as the clinical history. Despite this, false-negative cases are inevitable, as certain subtypes of breast cancer, including ductal carcinoma in situ, invasive lobular carcinoma, and certain well-differentiated invasive cancers, may demonstrate little to no enhancement at MRI, owing to differences in angiogenesis and neovascularity. MRI is a valuable diagnostic tool in breast imaging. However, MRI should continue to be used as a complementary modality, with mammography and US, in the detection of breast cancer. ©RSNA, 2021.

Multicenter Evaluation of Breast Cancer Screening with Digital Breast Tomosynthesis in Combination with Synthetic versus Digital Mammography.

BackgroundDigital breast tomosynthesis (DBT) combined with digital mammography (DM) is increasingly used in the United States instead of DM alone for breast cancer screening. Early screening outcomes incorporating synthetic mammography (SM) with DBT have suggested that SM is an acceptable non-radiation dose alternative to DM.PurposeTo compare multicenter outcomes from breast cancer screening with SM/DBT versus DM/DBT.Materials and MethodsThis was a retrospective study of consecutive screening mammograms obtained at two institutions. Eligible studies consisted of 34 106 DM/DBT examinations between October 3, 2011, and October 31, 2014, and 34 180 SM/DBT examinations between January 7, 2015, and February 2, 2018, at the University of Pennsylvania and 51 148 DM/DBT examinations between January 1, 2012, and May 31, 2016, and 31 929 SM/DBT examinations between June 1, 2016, and March 30, 2018, at the University of Vermont. Demographics of women who attended screening and results from screening were recorded. Recall rate, biopsy rate, false-negative rate, cancer detection rate, positive predictive value, sensitivity, and specificity were calculated according to modality and institution. Descriptive statistics, χ2 tests, and logistic regression were used in analysis.ResultsThe study included 151 363 screening examinations among 151 363 women (mean age, 58.1 years ± 10.9 [standard deviation]). The unadjusted recall rate was lower with SM/DBT than with DM/DBT (7.0% [4630 of 66 109 examinations] for SM/DBT vs 7.9% [6742 of 85 254 examinations] for DM/DBT; P < .01). However, after multivariable adjustment, SM/DBT was associated with a slightly higher recall rate compared with DM/DBT (adjusted odds ratio [OR], 1.06; adjusted 95% CI: 1.01, 1.11; P = .02). Similarly, after multivariable adjustment, SM/DBT was associated with slightly lower specificity compared with DM/DBT (adjusted OR, 0.95; adjusted 95% CI: 0.90, 0.99; P = .02). There was no statistically significant difference in biopsy rate (P = .54), false-negative rate (P = .38), cancer detection rate (P = .55), invasive or in situ cancer detection rate (P = .52 and P = .98, respectively), positive predictive value (P = .78), or sensitivity (P = .33) for SM/DBT versus DM/DBT overall or within either institution (P > .05 for all).ConclusionBreast cancer screening performance is maintained within benchmarks when synthetic mammography replaces digital mammography in digital breast tomosynthesis imaging.© RSNA, 2020Online supplemental material is available for this article.See also the editorial by Lång in this issue.

Five Consecutive Years of Screening with Digital Breast Tomosynthesis: Outcomes by Screening Year and Round.

Background Limited data exist beyond prevalence rounds of digital breast tomosynthesis (DBT) screening. Purpose To compare DBT outcomes over multiple years and rounds to outcomes of digital mammography (DM) screening. Materials and Methods Retrospective analysis included 1 year of DM and 5 years of DBT screening (September 2011 to September 2016); 67 350 examinations were performed in 29 310 women. Recall rate (RR) percentage, cancer detection rate (CDR) per 1000 women screened, false-negative rate per 1000 women screened, positive predictive value of recall (PPV1) percentage, positive predictive value of biopsies performed percentage, sensitivity, and specificity were calculated. Cancers diagnosed within 1 year of screening were captured by means of linkage to state cancer registry, and biologic characteristics were grouped by prognostic factors. Performance trends across DBT rounds were compared with those from DM rounds by using logistic regression to account for examinations in the same woman. Analyses were adjusted for age, race, breast density, baseline examination, and reader. Results There were 56 839 DBT and 10 511 DM examinations. The mean patient age (± standard deviation) was 56 years ±11 for the entire cohort, 55 years ±11 for the DBT group, and 57 years ±11 for the DM group. RRs were significantly lower for the DBT group (8.0%, 4522 of 56 839; 95% confidence interval [CI]: 7.7, 8.2) than for the DM group (10.4%, 1094 of 10 511; 95% CI: 9.8, 11.0) (P < .001). CDRs were higher with DBT (6.0 per 1000 women screened; 95% CI: 5.4, 6.7 per 1000 women screened; 340 of 56 839) than with DM (5.1 per 1000 women screened; 95% CI: 3.9, 6.6 per 1000 women screened; 54 of 10 511) (P = .25), but this difference was not statistically significant. Both RR and CDR remained improved compared with DM for 5 years of DBT at the population level. False-negative rates were slightly lower for DBT (0.6 per 1000 women screened; 95% CI: 0.4, 0.8 per 1000 women screened; 33 of 56 839) than DM (0.9 per 1000 women screened; 0.4, 1.6 per 1000 women screened; nine of 10 511) overall (P = .30), but the difference was not statistically significant. In adjusted analyses, RR, biopsy recommendation rates, and PPV1 were improved for DBT versus DM (P ≤ .001). Compared with DM, a higher proportion of DBT-detected cancers were invasive (70% [238 of 340] vs 68.5% [37 of 54]) and had poor prognoses characteristics (32.6% [76 of 233] vs 25.0% [nine of 36]). Conclusion Favorable outcomes with digital breast tomosynthesis screening were sustained over multiple years and rounds. Digital breast tomosynthesis screening was associated with detection of a higher proportion of poor-prognosis cancers than was digital mammography. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Moy and Heller in this issue.

Imaging With Synthesized 2D Mammography: Differences, Advantages, and Pitfalls Compared With Digital Mammography.

OBJECTIVE: Synthesized 2D (s2D) mammography is rapidly replacing digital mammography in breast imaging with digital breast tomosynthesis (DBT) to reduce radiation dose and maintain screening outcomes. We illustrate variations in the appearance of s2D and digital mammograms to aid in implementation of this technology. CONCLUSION: Despite subjective differences in the appearance of s2D and digital mammograms, early outcomes of screening using s2D mammography and DBT are not inferior to those achieved with digital mammography and DBT. Understanding these variations may aid in implementing this technique and improving patient outcomes.

Implementation of Synthesized Two-dimensional Mammography in a Population-based Digital Breast Tomosynthesis Screening Program.

Purpose To evaluate the early implementation of synthesized two-dimensional (s2D) mammography in a population screened entirely with s2D and digital breast tomosynthesis (DBT) (referred to as s2D/DBT) and compare recall rates and cancer detection rates to historic outcomes of digital mammography combined with DBT (referred to as digital mammography/DBT) screening. Materials and Methods This was an institutional review board-approved and HIPAA-compliant retrospective interpretation of prospectively acquired data with waiver of informed consent. Compared were recall rates, biopsy rates, cancer detection rates, and radiation dose for 15 571 women screened with digital mammography/DBT from October 1, 2011, to February 28, 2013, and 5366 women screened with s2D/DBT from January 7, 2015, to June 30, 2015. Two-sample z tests of equal proportions were used to determine statistical significance. Results Recall rate for s2D/DBT versus digital mammography/DBT was 7.1% versus 8.8%, respectively (P < .001). Biopsy rate for s2D/DBT versus digital mammography/DBT decreased (1.3% vs 2.0%, respectively; P = .001). There was no significant difference in cancer detection rate for s2D/DBT versus digital mammography/DBT (5.03 of 1000 vs 5.45 of 1000, respectively; P = .72). The average glandular dose was 39% lower in s2D/DBT versus digital mammography/DBT (4.88 mGy vs 7.97 mGy, respectively; P < .001). Conclusion Screening with s2D/DBT in a large urban practice resulted in similar outcomes compared with digital mammography/DBT imaging. Screening with s2D/DBT allowed for the benefits of DBT with a decrease in radiation dose compared with digital mammography/DBT. © RSNA, 2016 An earlier incorrect version of this article appeared online. This article was corrected on August 11, 2016.

Early discussion of breast density and supplemental breast cancer screening: is it possible?

The purpose of this study is to determine whether it is possible to make breast cancer screening more efficient in those with dense breasts. Over 12 states require that patients with dense breasts receive notification about their breast density in lay letters that are sent after the screening mammogram. Some of these letters advise patients to speak with their primary care providers about the possibility of supplemental breast cancer screening. We sought to determine whether primary care providers can discuss breast density and recommend supplemental breast cancer screening using the density of the previous mammography. This would reduce the burden of additional appointments and might increase the number of patients choosing to have supplemental screening. The mammographic breast density of 250 consecutive patients from May 2011 to September 2011 was compared with the immediate prior mammogram. Patients whose prior mammograms were more than 36 months prior or less than 8 months prior to the current exam were excluded, leaving 217 patients. The proportion of patients with breast density change was analyzed. The concordance of breast density between the two exams was assessed and the effects of patient age and the length of time between mammograms were examined. The breast density of the current and most recent prior mammogram was stable for 86.6% of patients. Neither age nor length of time between mammograms affected concordance. Primary care providers can decrease the need for multiple appointments and decrease patient anxiety by discussing breast density and screening choices prior to the patient's screening mammography. The great majority of patients will receive the correct information about their breast density by using a prior report.

Breast Imaging Fellowship Virtual Interviews: The Program Director's Perspective.

OBJECTIVE: To evaluate breast imaging fellowship program directors' perspectives on the virtual interview process. METHODS: A 20-question survey constructed by members of the Fellowship Match Committee of the Society of Breast Imaging was distributed to all 99 breast imaging program directors registered with the Society. An initial e-mail with a link to the survey was distributed on September 9, 2022, and the survey was closed on October 1, 2022. Results were compiled and a descriptive statistical analysis was performed utilizing Microsoft Excel. RESULTS: There were 63 total responses (63/99, 64% response rate). There was a wide distribution in both the number of applications received and the number of interviews each program offered. Just under a fifth (12/63, 19%) of programs received 1 to 5 applications, whereas a quarter (16/63, 25%) received over 40 applications. In contrast, over a quarter (17/63, 27%) of programs interviewed 1 to 5 applicants, and only a small number (3/63, 5%) interviewed over 40 applicants. When reporting what worked best with the virtual interview process, the responses fell into the following 4 categories: efficiency, flexibility, virtual format, or other. When reporting what did not work well, the most common response (14/37, 38%) was conveying the atmosphere of the program in the virtual setting. CONCLUSION: This study provides an assessment of the virtual interview experience from the perspective of breast imaging fellowship programs, which may be useful in optimizing future interview experiences for programs and applicants.

Opinions on the Assessment of Breast Density Among Members of the Society of Breast Imaging.

OBJECTIVE: Dense breast decreases the sensitivity and specificity of mammography and is associated with an increased risk of breast cancer. We conducted a survey to assess the opinions of Society of Breast Imaging (SBI) members regarding density assessment. METHODS: An online survey was sent to SBI members twice in September 2020. The survey included active members who were practicing radiologists, residents, and fellows. Mammograms from three patients were presented for density assessment based on routine clinical practice and BI-RADS fourth and fifth editions. Dense breasts were defined as heterogeneously or extremely dense. Frequencies were calculated for each survey response. Pearson's correlation coefficient was used to evaluate the correlation of density assessments by different definitions. RESULTS: The survey response rate was 12.4% (357/2875). For density assessments, the Pearson correlation coefficients between routine clinical practice and BI-RADS fourth edition were 0.05, 0.43, and 0.12 for patients 1, 2, and 3, respectively; these increased to 0.65, 0.65, and 0.66 between routine clinical practice and BI-RADS fifth edition for patients 1, 2, and 3, respectively. For future density grading, 79.0% (282/357) of respondents thought it should reflect both potential for masking and overall dense tissue for risk assessment. Additionally, 47.1% (168/357) of respondents thought quantitative methods were of use. CONCLUSION: Density assessment varied based on routine clinical practice and BI-RADS fourth and fifth editions. Most breast radiologists agreed that density assessment should capture both masking and overall density. Moreover, almost half of respondents believed computer or artificial intelligence-assisted quantitative methods may help refine density assessment.

Outcomes of COVID-19 Vaccination-Related Incidental Axillary Adenopathy in Women Undergoing Breast MRI.

OBJECTIVE: To assess the frequency, management, and early outcomes of COVID-19 vaccine-related adenopathy on breast MRI. METHODS: This IRB-exempt retrospective study reviewed patients who underwent breast MRI following COVID-19 vaccine approval in the U.S. from December 14, 2020, to April 11, 2021 (N = 1912) and compared patients who underwent breast MRI the year prior to the pandemic, March 13, 2019, to March 12, 2020 (N = 5342). Study indication, patient age, date of study, date and type of vaccination(s), time difference between study and vaccinations, lymph node-specific and overall management recommendations, and outcomes of additional examinations were recorded. Differences in the final assessment categories between the subjects scanned pre-pandemic and post-vaccine were compared using the Fisher exact test. RESULTS: Vaccine-related adenopathy was mentioned in 67 breast MRI reports; only 1 in the pre-pandemic group. There were no clinically relevant differences in patient demographics between groups. There was a statistically significant increase in BI-RADS 0 assessments between the pre-pandemic and post-vaccine approval groups-0.8% (45/5342) versus 1.8% (34/1912) (P = 0.001) and BI-RADS 3 assessments-6.5% (348/5342) versus 9.2% (176/1912) (P < 0.0001). Of the 29 patients who underwent additional imaging (range, 2-94 days following MRI) and the 2 patients who underwent biopsy, 47% (31/66), none were found to have malignant adenopathy. CONCLUSION: COVID-19 vaccination is associated with transient axillary adenopathy of variable duration. This leads to additional imaging in women undergoing breast MRI, so far with benign outcomes, and this may affect audits of outcomes of MRI.

Characterization of the imaging settings in screening mammography using a tracking and reporting system: A multi-center and multi-vendor analysis.

A tracking and reporting system was developed to monitor radiation dose in X-ray breast imaging. We used our tracking system to characterize and compare the mammographic practices of five breast imaging centers located in the United States and Brazil. Clinical data were acquired using eight mammography systems comprising three modalities: computed radiography (CR), full-field digital mammography (FFDM), and digital breast tomosynthesis (DBT). Our database consists of metadata extracted from 334,234 images. We analyzed distributions and correlations of compressed breast thickness (CBT), compression force, target-filter combinations, X-ray tube voltage, and average glandular dose (AGD). AGD reference curves were calculated based on AGD distributions as a function of CBT. These curves represent an AGD reference for a particular population and system. Differences in AGD and imaging settings were attributed to a combination of factors, such as improvements in technology, imaging protocol, and patient demographics. The tracking system allows the comparison of various imaging settings used in screening mammography, as well as the tracking of patient- and population-specific breast data collected from different populations.

Survey Results Regarding Uptake and Impact of Synthetic Digital Mammography With Tomosynthesis in the Screening Setting.

Synthesized digital mammography (SM) was developed to replace digital mammography (DM) in digital breast tomosynthesis (DBT) imaging to reduce radiation dose. This survey assessed utilization and attitudes regarding SM in DBT screening. The study was institutional review board exempt. An online survey was sent to members of the Society of Breast Imaging in June 2018. Questions included practice information, utilization of DBT and SM, perception of change in recall rates (RRs) and cancer detection rates (CDRs) with SM-DBT versus DM-DBT, and attitudes regarding SM versus DM in DBT screening. χ2 Tests were used to compare response frequencies across groups. In all, 312 of 2,600 Society of Breast Imaging members responded to the survey (12%). Of respondents, 96% reported DBT capability, and 83% reported SM capability. Of those without SM, the most cited reasons were cost or administration and image quality concerns (both 32%). In addition, 40% reported combined SM and DM use in DBT screens, and 52% reported SM use without DM in the majority of DBT screens. The overall satisfaction with SM was 3.4 of 5 (1-5 scale). Most cited SM advantages were decreased dose (85%) and increased lesion conspicuity (27%). The most cited SM disadvantages were calcification characterization (61%) and decreased image quality (31%). Most respondents were unsure if CDRs changed (44%) and RR changed (30%) with few reporting adverse outcomes (6% RR increase, 1% CDR decrease). Most radiologists screening with DBT have SM, but only one-half have replaced DM with SM. Despite few reported adverse screening outcomes with SM-DBT, radiologists have concerns about image quality, specifically calcification characterization.

Abbreviated Breast Magnetic Resonance Imaging for Supplemental Screening of Women With Dense Breasts and Average Risk.

PURPOSE: Although mammography is the standard of care for breast cancer screening, dense breast tissue decreases mammographic sensitivity. We report the prevalent cancer detection rate (CDR) from the first clinical implementation of abbreviated breast magnetic resonance imaging (AB-MR) as a supplemental screening test in women with dense breasts. METHODS: The study was approved by the institutional review board and is Health Insurance Portability and Accountability Act complaint. This retrospective review includes women who were imaged between January 1, 2016 and February 28, 2019. On a 1.5 Tesla magnet, the imaging protocol consisted of three sequences: Short-TI Inversion Recovery (STIR), precontrast, and postcontrast. A subtraction sequence and a maximum intensity projection were generated. We report the patient-level CDR and the positive predictive value of AB-MR examinations after negative/benign digital breast tomosynthesis (DBT). RESULTS: Out of 511 prevalent rounds of AB-MR examinations, 36 women were excluded. The remaining 475 asymptomatic women with dense breasts had negative/benign DBT examinations before the AB-MR. There were 420 of 475 (88.4%) benign/negative examinations, 13 of 475 (2.7%) follow-up recommendations, and 42 biopsy recommendations. Thirty-nine biopsies were completed, resulting in 12/39 (30.8%) malignancies in 12 women: seven invasive carcinomas and five ductal carcinoma in situ. One additional patient was diagnosed with invasive ductal carcinoma at the time of 6-month follow-up. The CDR was 27.4 per 1,000 (13 of 475; 95% CI, 16.1 to 46.3). The size of invasive carcinomas ranged from 0.6-1.0 cm (mean, 0.5 cm). Of the seven women who underwent surgical evaluation of the axilla, zero of seven patients had positive nodes. There were no interval cancers at 1-year follow-up. CONCLUSION: Preliminary results from clinical implementation of screening AB-MR resulted in a CDR of 27.4/1,000 at the patient level after DBT in women with dense breasts. Additional evaluation is warranted.

First-Year Radiology Residents Teaching Anatomy to First-Year Medical Students: A Symbiotic Relationship.

OBJECTIVES: Our institution has developed an educational program in which first-year radiology residents teach first-year medical students during gross anatomy laboratory sessions. The purpose of this study is to assess the impact of this program on medical student knowledge and perceptions of radiology, and on resident attitudes toward teaching. MATERIALS AND METHODS: First-year resident pairs taught small groups of medical students during weekly 15-minute interactive sessions, and were evaluated on teaching skills by senior residents. A survey about attitudes toward radiology and a knowledge quiz were sent to the medical students, and a survey about attitudes toward teaching was sent to the first-year radiology residents, both pre-course and post-course. RESULTS: Students' radiology knowledge significantly increased between the pre-course and post-course survey across all categories tested (P < 0.001). Additionally, there were significant improvements in terms of students' confidence in radiologic anatomy skills, perceived importance of radiology for medical training, familiarity with the field of radiology, and perception that radiologists are friendly (P < 0.001). Radiology residents felt more confident in their teaching proficiency (P < 0.001) by the conclusion of the course. CONCLUSIONS: Resident-led small-group teaching sessions during anatomy laboratory are mutually beneficial for medical students and radiology residents. The program also allows radiology residents to be exposed early on in residency to teaching and academic medicine.

Microglandular Adenosis: A Possible Non-Obligate Precursor to Breast Carcinoma With Potential to Either Luminal-Type or Basal-Type Differentiation.

Microglandular adenosis (MGA) of the breast is exceedingly rare, with only a few case reports and series published to date. Previous studies have elegantly demonstrated the progression of benign MGA to atypical MGA to MGA-in situ carcinoma to invasive carcinoma and therefore suggest MGA as a possible non-obligate precursor lesion to a subset of breast carcinomas. Immunohistochemically, MGA is negative for estrogen receptor (ER), progesterone receptor (PR), and HER2-neu oncoprotein expression, and carcinomas arising in the setting of MGA are often reported to be triple negative. In this article, we present a unique case of an ER+/PR+/HER2- invasive carcinoma associated with MGA and atypical MGA. Our case highlights the diagnostic pitfall of MGA and suggests that MGA is a heterogeneous group of lesions with potential for either luminal-type or basal-type differentiation during progression to breast carcinoma.