Timing and Duration of Axillary Lymph Node Swelling After COVID-19 Vaccination: Japanese Case Report and Literature Review

Abstract

Background/Aim: COVID-19 vaccination is now performed in most of the world to limit the spread of the disease. The first mRNA vaccine was approved in clinical settings and has specific side effects including axillary lymph node swelling, which can be misdiagnosed as breast cancer metastasis. The timing of axillary lymph node swelling and its duration are unclear. Here, we present a Japanese case and review of the existing literature. Case Report: We report the case of a 67-year-old woman with breast calcification. She had regular follow ups in our hospital for this calcification and received ultrasonography of the breast and axilla at every visit. She visited 6 months before having her COVID-19 vaccination, and 7 days and 6 months after the first COVID-19 vaccination. She had a swollen axillary lymph node 7 days after the first vaccination, which although it was improved, remained for 6 months. Conclusion: Axillary lymph node swelling occurred 7 days after vaccination and remained up to 6 months after it.COVID-19 first occurred in Wuhan in December 2019 (1), and the pandemic continues to develop globally 2 years later. The new Omicron strain has been confirmed and a new wave of the pandemic is spreading. In Japan, "the 6th wave" has occurred in some prefectures. The Omicron strain can infect those who have received two COVID-19 vaccinations; therefore, the COVID-19 pandemic might continue in the near future.COVID-19 vaccination started in the late 2020 in some countries and in Japan in early 2021. Medical staff were vaccinated first followed by elderly people, and then adults in the general public. Most Japanese have received two vaccinations. Currently, a third vaccination is being offered.One of the COVID-19 vaccines available is an mRNA vaccine (2), which has been approved for the first time in a clinical setting, and in Japan only the mRNA COVID-19 vaccine was initially used. It has specific side effects, such as fatigue, fever, injection site swelling, and axillary lymph node swelling, which can be confusing for breast oncologists. Previous studies reported axillary lymph node swelling after vaccination; however, when the swelling occurs or is cleared remains unclear. We experienced a case who had received COVID-19 vaccination whose axillary lymph node situation was assessed by ultrasonography continuously during breast calcification follow up during the pandemic. Here, we report this case and provide a literature review about the influence of the COVID-19 vaccine on axillary lymph nodes.

Coronavirus disease 2019 (COVID-19) vaccination-induced unilateral axillary lymphadenopathy: case series with follow-up and literature review

“…According to a retrospective review of 951 patients who underwent 18 Several studies reported on the expected time course for resolution of lymphadenopathy. 10,13,24,25 In the largest study on axillary lymphadenopathy following COVID-19 vaccination with long-term follow-up of 6 months, the time to resolution of reactive lymphadenopathy was variable, with persistent lymphadenopathy observed up to 43 weeks following vaccination. Lymphadenopathy was found as early as 1 day after the first dose of vaccine and as late as 71 days after the second dose.…”

Oncogenesis and autoimmunity as a result of mRNA COVID-19 vaccination

“…A case study involved a 64-year-old woman with breast calcification who was assessed for breast cancer via ultrasonography six months before her first SARS-CoV-2 vaccine, and again 7 days after the vaccine due to obvious lymph node enlargement in the vaccinated arm. Six months later, a follow-up examination revealed that the lymph node was still swollen, although somewhat reduced, even though there was no evidence of breast cancer [92].…”

Bilateral Axillary Nodal Uptake on 99mTc–White Blood Cell Study Secondary to COVID-19 mRNA Vaccination

“…The exact mechanism of how the COVID-19 vaccine may cause lymphadenopathy and increased WBC uptake is unclear, although it is postulated that the increased immune response following vaccination causes an immune mediated inflammatory response in the area surrounding the vaccination site, and immune cells in the nearby nodes may proliferate as they become exposed to the vaccine. This type of reactive lymphadenopathy has been seen in multiple other vaccines in the past including measles, anthrax, H1N1, bacille Calmette-Guérin, and human papillomavirus vaccines 11,12 . Post-COVID reactive axillary lymphadenopathy has been reported to persist longer than 6 months and up to 43 weeks after vaccination 11,12 .…”

“…This type of reactive lymphadenopathy has been seen in multiple other vaccines in the past including measles, anthrax, H1N1, bacille Calmette-Guérin, and human papillomavirus vaccines. 11 , 12 Post-COVID reactive axillary lymphadenopathy has been reported to persist longer than 6 months and up to 43 weeks after vaccination. 11 , 12 The Moderna mRNA vaccine was also significantly more associated with lymphadenopathy compared with Pfizer.…”

“… 11 , 12 Post-COVID reactive axillary lymphadenopathy has been reported to persist longer than 6 months and up to 43 weeks after vaccination. 11 , 12 The Moderna mRNA vaccine was also significantly more associated with lymphadenopathy compared with Pfizer. 12 Awareness of potential lymphadenopathy post–COVID-19 vaccine is important as it can be confused with metastasis or other false-positive results.…”