Axillary Lymphadenopathy After Coronavirus Disease 2019 Vaccinations in Patients With Thoracic Malignancy: Incidence, Predisposing Factors, and Imaging Characteristics
Axillary lymphadenopathy from coronavirus disease 2019 (COVID-19) vaccine is an emerging phenomenon during unprecedented mass vaccinations, which can be incidentally found on computed tomography (CT) scans. This study investigated the incidence, predisposing factors, and imaging characteristics of vaccine-related axillary lymphadenopathy in patients with thoracic malignancy who underwent CT scans before and after COVID-19 vaccinations.
Methods
The study included patients with thoracic malignancies who received two doses of mRNA-based COVID-19 vaccinations and had prevaccine and postvaccine chest CT scans. Postvaccine chest CT scan results were reviewed for increase in size of lymph nodes in the axilla and subpectoral areas, comparing with the prevaccine scan results. The cases with lymphadenopathy were further reviewed independently by two radiologists referring to clinical information to find whether lymphadenopathy was attributed to the vaccinations.
Results
Vaccine-related axillary lymphadenopathy was noted in 21 of 232 patients (9.0%). The median short-axis diameter of the largest node was 7 mm (range: 5–14 mm). The median number of increased nodes was 4 (range: 1–10). The median time to the postvaccine scan revealing lymphadenopathy was 1.7 weeks (range: −2.9 to 6.6) from the second dose. Vaccine-related lymphadenopathy was noted more often in women than in men (18 of 144, 12.5% versus 3 of 88, 3.4%, respectively; p = 0.019) and with mRNA-1273 vaccines than BNT162b2 vaccines (6 of 28, 21% versus 15 of 204, 7.4%, respectively; p = 0.026).
Conclusions
The incidence of lymphadenopathy was 9%, with a median onset time of 1.7 weeks after the second vaccine dose. Female sex and vaccine type (mRNA-1273 vaccine) were associated with higher frequency of lymphadenopathy, providing initial observations to inform further investigations in larger cohorts.
Keywords
COVID-19
Vaccinations
Lymphadenopathy
Computed tomography
mRNA vaccine
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Disclosure: Dr. Nishino reports serving as a consultant to Daiichi Sankyo and AstraZeneca and receiving research grants from Merck, Canon Medical Systems, AstraZeneca, and Daiichi Sankyo. Dr. Hatabu reports receiving research funding from Canon Inc., Canon Medical Systems, and Konica-Minolta and serving as a consultant to Canon Medical Systems and Mitsubishi Chemical Inc. Dr. Awad reports serving as a consultant/advisory board for Genentech, Bristol-Myers Squibb, Merck, AstraZeneca, Maverick, Blueprint Medicine, Syndax, Ariad, Nektar, Gritstone, ArcherDx, Mirati, NextCure, EMD Serono, and Hengrui. The remaining authors declare no conflict of interest.
