Evaluating the preoperative breast cancer characteristics affecting the accuracy of axillary ultrasound staging.

We evaluate the preoperative breast cancer (BC) characteristics that affect the diagnostic accuracy of axillary ultrasound (US) and determine the reliability of US in the different subgroups of BC patients. Axillary US assessments in women with invasive BC diagnosed between 2009 and 2016 in a single institution were retrospectively reviewed. The diagnostic accuracy of axillary US was obtained using surgical nodal histology as the gold standard. Preoperative breast tumor sonographic and histological factors affecting axillary US diagnostic accuracy were examined. Of the 605 newly diagnosed invasive BC cases reviewed, 251 (41.5%) had nodal metastases. Axillary US sensitivity was 75.7%, specificity 92.9%, positive predictive value 88.4%, negative predictive value 84.4%, and false-negative rate 24.3%. Lower US sensitivity was seen with invasive lobular cancer (ILC) (P = .043), grade I/II, (P = .021), unifocal (P = .039), and smaller tumors (P < .001). US specificity was lower in grade III (P < .001), estrogen receptor (ER)-negative (P < .001), progesterone receptor (PR)-negative (P = .004), HER2-positive (P = .015), triple-negative (P = .001), and larger breast tumors (P < .001). US has moderate sensitivity and good specificity in detecting metastatic axillary lymph nodes. Based on preoperative cancer characteristics, US was less sensitive for nodal metastases from ILC, unifocal, lower grade, and smaller breast tumors. It was also less specific in grade III, ER-negative, PR-negative, HER2-positive, triple-negative, and larger breast tumors. Caution is suggested in interpreting the US axillary findings of patients with these preoperative tumor features.

Breast Imaging in the Time of COVID-19: A Singapore-based Breast Center's Experience in the Midst of a Pandemic.

The emergence of the COVID-19 pandemic presented new and yet uncharted challenges to the field of radiology, and consequently to breast imaging as a subspecialty. Maintaining a certain standard of care whilst ensuring the safety of patients and staff in our small Singapore-based breast imaging center are equally important and has resulted in modifications of our clinical practice and workflows. Screening patients for COVID-19 symptoms, risk factors, and potential exposure history has become paramount. Workflow changes have also included progressively deferring, and in some cases halting, nonessential services such as biopsies deemed to have a low risk of malignancy, routine follow-up imaging in postoperative patients or those with prior Breast Imaging Reporting and Data System 3 findings, and mammographic screening. Breast radiologists within our practice are also adapting to the changing landscape by playing a more active role in general radiology and emergency department reporting in order to reduce turnaround time and facilitate the discharge of inpatients. We have also enabled a sense of geographical segregation within our breast center to reduce potential exposure and cross-contamination risks. Although the near future remains uncertain, breast imaging within the broader scope of radiology practice will have to continually adjust to meet the ever-changing realities as this pandemic evolves.

Preoperative predictors of high and low axillary nodal burden in Z0011 eligible breast cancer patients with a positive lymph node needle biopsy result.

BACKGROUND: Z0011 trial showed that early breast cancer patients with low axillary nodal burden, may be spared an axillary lymph node dissection with no survival compromise. Axillary lymph node dissection can be reserved for patients with a high axillary nodal burden. We aim to determine the preoperative factors that could distinguish between low and high axillary nodal burden in Z0011 eligible patients with a needle biopsy proven metastatic node. METHOD: Patients who fulfilled Z0011 trial criteria with a positive lymph node needle biopsy and had axillary lymph node dissection (ALND) were recruited. These patients were classified into low and high nodal burden subgroups, defined as having 1-2 and ≥3 metastatic lymph nodes, respectively. The clinical, radiological and pathological features between the 2 subgroups were compared. RESULTS: 70 (40%) and 105 (60%) patients had low and high nodal burden respectively. The high nodal burden subgroup was more likely to have on ultrasound ≥3 abnormal lymph nodes (37.14% versus 4.29%) (P < 0.0001) and maximum cortical thickness >4 mm (31.43% versus 10.0%) (P = 0.0036). Multivariate analysis revealed abnormal lymph nodes ≥3 to have an odds ratio of 20.72 (95% CI 5.91-72.65) P < 0.0001. CONCLUSION: ≥3 abnormal lymph nodes on ultrasound was the most significant predictor of high nodal burden subgroup in Z0011 eligible patients with a positive lymph node needle biopsy. This information could allow this subgroup to proceed to an upfront ALND and avoid the need of a sentinel lymph node biopsy in the post Z0011 trial era.

Mammographic and sonographic features of fat necrosis of the breast.

Imaging features of fat necrosis vary depending on its stage of evolution and can mimic malignancy in late stages. Imaging may suffice to differentiate fat necrosis in the early stages from malignancy and thus avoid unnecessary biopsy. In this pictorial essay, we present combination of benign features in mammography and/or ultrasonography (USG) that can lead to imaging diagnosis of fat necrosis. The follow-up imaging features of fat necrosis which mirror its pathophysiological evolution have also been demonstrated. To summarize, in the appropriate clinical setting, no mammographic features suspicious for malignancy should be present. When the typical mammographic features are not present, USG can aid with the diagnosis and follow up USG can confirm it.