COVID-19 Vaccination Induced Lymphadenopathy in a Specialized Breast Imaging Clinic in Israel: Analysis of 163 cases

Abstract

Introduction: Following vaccination of Israeli population with Pfizer-BioNTech COVID-19 Vaccine, an unusual increase in axillary-lymphadenopathy was noted. This study assesses the rate and magnitude of this trend from breast-imaging standpoint. Materials and Methods: Participants undergoing breast-imaging, in whom isolated axillary-lymphadenopathy was detected were questioned regarding SARS-CoV-2 vaccine to the ipsilateral arm. Patients’ and imaging characteristics were statistically compared. In order to perform a very short-term follow-up, twelve healthy vaccinated medical staff-members, underwent axillary-ultrasound shortly after the second dose, and follow-up. Results: Axillary-lymphadenopathy attributed to vaccination was found in 163 women undergoing breast-imaging, including BRCA -carriers. During the study, number of detected lymphadenopathies increased by 394% (p=0.00001) in comparison with previous two consecutive years. Mean cortical-thickness of abnormal lymph-nodes after second dose vaccination was 5±2 mm. Longer lymph-node diameter after second vaccination was noted (from 15±5 mm, to 18±6 mm, p=0.005). In the subgroup of medical staff members, following trends were observed: in patients with positive antibodies, lymph-node cortical-thickness was larger than patients with negative serology (p=0.03); lymph-node cortical-thickness decreased in 4-5 weeks follow-up (p=0.007). Lymphadenopathy was evident on mammography in only 49% of cases. Discussion: Vaccine-associated lymphadenopathy is an important phenomenon with great impact on breast-imaging clinic workload. Results suggest the appearance of cortical thickening shortly after both doses. Positive serology is associated with increased lymph-node cortical-thickness. In asymptomatic vaccinated women with ipsilateral axillary-lymphadenopathy as the only abnormal finding, radiological follow-up is probably not indicated. BRCA -carriers, although at higher risk for breast-cancer, should probably receive the same management as average-risk patients.

Axillary Lymphadenopathy on Ultrasound after COVID-19 Vaccination and Its Influencing Factors: A Single-Center Study

“…The majority of axillary lymphadenopathy (96%) in the current study was subclinical and detected by ultrasound. This was consistent with the results of another study wherein 97.5% of lymphadenopathy in 163 cases in a breast imaging clinic were only detected by imaging such as ultrasound, magnetic resonance imaging, or mammography [ 1 ].…”

“…In conjunction with the massive administration of coronavirus disease 2019 (COVID-19) vaccines, we observed an unusual increase in the number of imaging-detected unilateral axillary lymphadenopathy cases at our breast imaging clinic. Vaccine-associated lymphadenopathy has also been recently reported as a frequent imaging finding after COVID-19 vaccination [ 1 , 2 , 3 ]. In clinical trials of the Moderna vaccine, axillary swelling or tenderness was reported in 11.6% and 16.0% of patients following the first and the second dose, retrospectively.…”

COVID-19 Vaccine-Associated Subclinical Axillary Lymphadenopathy on Screening Mammogram

“…As she was asymptomatic, had her screening mammogram not been performed or significantly delayed, her breast cancer would have not been detected, likely resulting in increased morbidity or mortality due to a delay in diagnosis. Additionally, presence of reactive lymphadenopathy does not exclude the possibility of malignancy 4 .…”

“…Women who have received either the Pfizer or Moderna COVID-19 vaccine have presented with unilateral axillary lymphadenopathy after both the first and second doses of these vaccines. A previous review study noted that this occurred most commonly in between 1-4 weeks post vaccination, and is usually subclinical in nature 3 , 4 . If the lymphadenopathy is due to an immune response from the vaccine, and not malignancy, this represents additional cost for the follow up diagnostic studies as well as undue psychological distress for the patient 5 .…”

Ultrasound Features to Differentiate COVID-19 Vaccine-Induced Benign Adenopathy from Breast Cancer Related Malignant Adenopathy

“…The changes in lymph node features after vaccination, reported in a study of 91 volunteer employees, include an increase in the lymph node size by 5.3 mm, increase in cortical thickness by 2.1 mm, increase in the number of visible lymph nodes by 1.8, and an overall increase in the associated Doppler signal [3] . Faermann et al reported that the mean cortical thickness of lymph nodes after vaccination was 5 mm ± 2 mm and that the longitudinal length of lymph nodes increased between the first and the second doses of a mRNA COVID-19 vaccine [4] . As reports of vaccine-induced reactive adenopathy increased, management recommendations were developed and modified regarding the need for imaging and biopsy [5] , [6] , [7] , [8] .…”