Cervical and Axillary Lymphadenopathy after Administrating mRNA BNT-162b2 Vaccine against COVID-19: Clinical and Sonographic Findings, Outcomes of Short-term Follow-up

ABSTRACT

Introduction: Vaccination plays an important role in all strategic actions against the COVID-19 pandemic. Despite the high safety and efficacy of vaccination, side effects of the vaccines may also occur. The purpose of this study was to evaluate the clinical and sonographic findings and short-term results of cervical and axillary lymphadenopathy after the BNT-162b2 mRNA vaccine. Materials and Methods: The patients who received at least one dose of BNT-162b2 mRNA vaccine between July-September 2021 and were detected to have ipsilateral axillary and cervical lymphadenopathy related closely to the vaccination period, were included in the study. Clinical characteristics, sonographic findings of lymphadenopathies, and short-term results were analyzed retrospectively. Results: A total of 13 patients [six females (46.2%), seven males (53.8%)] were evaluated in the present study. Mean age of the patients was 41.9 years (min-max= 20-56). Median time-lapse between vaccination and presentation to hospital was six days, and seven (53.8%) patients presented with symptoms and findings after the first dose, and six patients (46.2%) after the second dose. Three (23.1%) axillary lymphadenopathies, and 10 (76.9%) cervical lymphadenopathies were detected. Sonographic examination revealed lymphadenopathies predominantly oval morphology (69.2%), asymmetric cortical thickening (61.5%), and hilar-type vascularization (69.2%). Mean time of regression was found 19.2 days (min-max= 10-35). Conclusion: Ipsilateral cervical and axillary lymphadenopathies may occur because of vaccines against COVID-19. The sonographic findings of these lymphadenopathies may not be distinguished clearly from malignant lymph nodes;and for this reason, close clinical and radiological follow-up would be appropriate to elucidate the process.