A single-center study revealed a low rate of axillary adenopathy in women who underwent screening or diagnostic mammography within 90 days of COVID-19 vaccination. The study was published as a letter to JAMA Oncology.

The authors noted that prior data had suggested the rate of vaccine-related adenopathy could be as high as 16%, but the current study revealed a rate of 3%.

In this retrospective study, researchers assessed axillary adenopathy in 750 women who had received at least 1 COVID-19 vaccine injection fewer than 90 days prior to screening or diagnostic mammography.

Of the 750 women evaluated, 23 (3%) had axillary adenopathy, and 2 were symptomatic.

“[T]his incidence is still higher than axillary adenopathy in otherwise normal mammography, which was reported as 0.02% to 0.04%,” the authors noted.

The authors also found that the presence of symptoms was associated with abnormal imaging (P =.01) but not with age (P =.29) or the type of vaccine received (P =.70).

There was also no significant difference in the incidence of adenopathy after the first or second dose of the vaccine (P =.34).

The median time from vaccination to mammography was significantly shorter in patients with adenopathy than in those without it — 10 days and 18 days, respectively (P <.001).

Additionally, adenopathy rates decreased as days from vaccination increased — 5.3% for 1-14 days, 2.9% for 15-28 days, and 0% for more than 28 days (P =.01).

These results suggest “routine inquiring about recent history of COVID-19 vaccination is warranted,” according to the authors.

“As COVID-19 vaccination is rolling out around the world, this study offers timing considerations and possible findings for breast imaging following vaccination,” the authors concluded. 

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Robinson KA, Maimone M, Gococo-Benore DA, Li Z, Advani PP, Chumsri S. Incidence of axillary adenopathy in breast imaging after COVID-19 vaccination. JAMA Oncol. Published online July 22, 2021. doi:10.1001/jamaoncol.2021.3127