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 prepandemic 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 prepandemic 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.

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.