Pearls and Pitfalls of Interpretation of Automated Breast US.

Dense breast tissue is an independent risk factor for breast cancer and reduces the sensitivity of mammography. Patients with dense breast tissue are more likely to present with interval cancers and higher-stage disease. Successful breast cancer screening outcomes rely on detection of early-stage breast cancers; therefore, several supplemental screening modalities have been developed to improve cancer detection in dense breast tissue. US is the most widely used supplemental screening modality worldwide and has been proven to demonstrate additional mammographically occult cancers that are predominantly invasive and node negative. According to the American College of Radiology, intermediate-risk women with dense breast tissue may benefit from adjunctive screening US due to the limitations of mammography. Several studies have demonstrated handheld US (HHUS) and automated breast US (AUS) to be comparable in the screening setting. The advantages of AUS over HHUS include lack of operator dependence and a formal training requirement, image reproducibility, and ability for temporal comparison. However, AUS exhibits unique features that can result in high false-positive rates and long interpretation times for new users. Familiarity with the common appearance of benign mammographic findings and artifacts, technical challenges, and unique AUS features is essential for fast, efficient, and accurate interpretation. The goals of this article are to (a) examine the role of AUS as a supplemental screening modality and (b) review the pearls and pitfalls of AUS interpretation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Breast MRI assists in decision-making for surgical excision of atypical ductal hyperplasia.

BACKGROUND: Atypical ductal hyperplasia diagnosed on percutaneous breast biopsy typically undergoes surgical excision, upgrading to invasive breast cancer or ductal carcinoma in situ in 10% to 53%. In efforts to limit excision to those with highest upgrade risk, we sought to determine if breast magnetic resonance imaging has value in predicting upgrade. In this study, we will describe magnetic resonance imaging presentation of atypical ductal hyperplasia and assess magnetic resonance imaging accuracy in predicting upgrade. METHODS: All female patients ≥18 years with atypical ductal hyperplasia on percutaneous breast biopsy undergoing magnetic resonance imaging from 2008 to 2020 were included. Patient demographics, imaging presentation, magnetic resonance imaging enhancement kinetic curves, and pathology features were captured. Categorical variables were analyzed using Fisher exact to test for association between variables and upgrade. Continuous variables were analyzed using t tests. RESULTS: Magnetic resonance imaging was performed for 125 percutaneous breast biopsy with atypical ductal hyperplasia: 67 after and 58 before atypical ductal hyperplasia diagnosis. On magnetic resonance imaging, atypical ductal hyperplasia site had no enhancement in 45 (36%), nonmass enhancement in 50 (40%), and mass enhancement in 30 (24%). In total, 28% had atypical ductal hyperplasia diagnosed by magnetic resonance imaging-guided percutaneous breast biopsy. Surgical excision was performed for 96 (76.8%) and 15 (15.6%) upgraded (11 ductal carcinoma in situ, 4 invasive breast cancer). All 15 upgrades had enhancement. Any kinetic pattern enhancement was significantly associated with upgrade (P = .009) with upgrade most strongly associated with type III washout. The lowest risk for upgrade was pure atypical ductal hyperplasia and no magnetic resonance imaging enhancement (0%, n = 25). CONCLUSIONS: Active monitoring may be safely offered to women with pure atypical ductal hyperplasia on percutaneous breast biopsy when magnetic resonance imaging shows no enhancement. Any enhancement at atypical ductal hyperplasia site, particularly type III washout kinetics, should continue to undergo excision.

Safety of de-escalation of surgical intervention for atypical ductal hyperplasia on percutaneous biopsy: One size does not fit all.

BACKGROUND: Oncologic safety of active monitoring (AM) for atypical ductal hyperplasia (ADH) on core-needle biopsy (CNB) is not well defined. We sought to define oncologic outcomes for AM to manage ADH meeting institutional predefined low-risk criteria (LOW). METHODS: ADH was diagnosed on CNB from 10/2015-03/2020. LOW (pure ADH, size <1 cm, >50% removed by CNB, <3 foci, and no necrosis) patients were offered AM; all others were recommended for surgical excision. Oncologic outcomes were compared for AM and surgery. RESULTS: 111 were included, 21 (19%) meeting LOW. AM occurred in 18 (86%) while 3 elected for excision (with 0% upgrade). Of the 18 LOW in AM, 2 required additional CNB (none at ADH site): 0% were diagnosed with cancer over median 23 month follow-up. CONCLUSIONS: There were no missed cancers at ADH site during AM for LOW, confirming the oncologic safety of AM in this select group.

Multidisciplinary Review of Intraductal Papilloma of the Breast can Identify Patients who may Omit Surgical Excision.

BACKGROUND: The purpose of this study was to define contemporary management recommendations regarding who would benefit from surgical excision of intraductal papilloma (IDP). METHODS: A prospective database from a single institution identified patients with IDP on percutaneous biopsy from February 2015 to September 2020. Categorical patient demographic, biopsy, and pathologic variables were analyzed using Fisher's exact test and continuous demographic and imaging variables using the Mann-Whitney U test. RESULTS: IDP was present in 416 biopsies, at a median age of 56 years. The median size was 0.9 cm, and the majority had greater than 50% of the target excised by biopsy. Surgical excision was performed for 124 of 416 biopsies (29.8%). Upgrade to malignancy was identified in 14 (11.3%): 8 to ductal carcinoma in situ (DCIS) and 6 to invasive cancer. Upgrade was significantly associated with concurrent ipsilateral breast cancer (p = 0.027), larger imaging size (p = 0.045), <50% excised with biopsy (p = 0.02), and atypia involving IDP (p = 0.045). Age, clinical presentation, and concurrent contralateral cancer were not significantly associated with upgrade. Lowest upgrade risk (0%) was in pure IDP ≤1 cm with >50% removed by biopsy. Of 401 biopsies that either did not upgrade or undergo excision, 7 (1.7%) developed subsequent breast cancer over a median follow-up of 23.5 months (interquartile range [IQR] 11,41), none at IDP site. CONCLUSIONS: After multidisciplinary review, the management of IDP can be stratified into low- and high-risk for upgrade groups using key criteria. Low-risk group may omit surgical excision, because those patients have 0% risk of upgrade over the limited short-term follow-up.

Ipsilateral and Concurrent Breast Cancer and Atypical Ductal Hyperplasia: Does Atypia Also Need Surgical Excision?

BACKGROUND: Standard-of-care management of atypical ductal hyperplasia (ADH) is surgical excision. Multiple studies have identified features of ADH in patients at low risk for upgrade who may benefit from omission of surgical excision. Patients with an ipsilateral breast cancer have been excluded from studies investigating observation for the management of ADH. METHODS: This was a retrospective review of women with both a breast cancer and an ipsilateral separate site of ADH diagnosed on percutaneous biopsy, who underwent excision of both sites from 2008 to 2018. Radiographic and pathologic features of ADH and cancer were analyzed, including imaging size, biopsy modality, distance between sites, cancer subtype, grade, prognostic markers, ADH foci, and presence of necrosis or micropapillary features. Final pathology at the ADH site was used to determine upgrade. Multivariable logistic regression was performed to identify variables significantly associated with ADH upgrade to malignancy. RESULTS: Among 62 women meeting the inclusion criteria, 11 (17.7%) upgraded to malignancy [9 ductal carcinoma in situ (DCIS), 2 invasive cancer] at the site of ADH. Upgrade was significantly higher with ipsilateral DCIS (p = 0.03), ultrasound biopsy at the ADH site (p = 0.01), and ADH with necrosis (p = 0.04). The group at lowest risk for upgrade had stereotactic biopsy and ADH without necrosis (0% upgrade). CONCLUSION: The presence of breast cancer does not significantly increase the likelihood for upgrade at a separate site of ipsilateral concurrent ADH above contemporary reported upgrade rates of ADH alone (10-30%). When considering breast conservation for breast cancer, omitting excision of the site of ADH can be considered when low-risk features are present.