Women who have undergone immunization for COVID-19 are more likely to experience a positive screening mammogram, according to a UCLA physician
“When you are vaccinated, your body initiates an immune response to the vaccine and lymph nodes can swell as that immune response is occurring,” said Dr. Hannah Milch, a radiologist and assistant clinical professor at the UCLA David Geffen School of Medicine. “When we read a mammogram, we catch some of the lymph nodes in your armpits, which is just a normal part of evaluating a mammogram.”
Milch first noticed the reaction in January among early adopters of the vaccine who were immunized in December.
“We’re trying to get a sense at UCLA of how long they stay swollen or enlarged after the COVID vaccine, but you would expect within some number of months that they would go back to normal,” she said. “It's definitely not something that would stay. It is a temporary phenomenon.”
Enlarged lymph nodes are just one side effect of the vaccine that has prompted concern.
Upon being vaccinated, young men are at a higher risk for myocarditis, also known as heart inflammation, according to media reports.
“A positive screening mammogram means we found something that requires further investigation, which can be stressful for sure,” Milch told the Southern California Record. “The vast majority of positives after a screening mammogram end up being benign.”
UCLA performs150 to 200 screening mammograms a day and 12% of results are positive or inconclusive, according to data from UCLA.
“When you’re vaccinated, your immune cells are in overdrive trying to create the protection you need in case you get the infection,” Milch said in an interview. “That causes immune tissue and lymph nodes to rev up as they're doing that work. Then they go back to normal when they're done doing the work.”
In California, some 24,577,801 people or 62% of the population have received one dose and statewide, 20,016,280 people or 50% are fully vaccinated, according to the state’s COVID dashboard.
“I think the reason this became such a phenomenon is that so many people were getting this vaccine all at once and it’s more than some run-of-the-mill vaccines in terms of the level of lymph node enlargement that we see,” Milch added.
Despite the risk for a false positive, Milch does not recommend delaying a breast cancer screening mammogram for too long.
“It's suggested but not at all required to schedule a screening exam four to six weeks following their second dose of the COVID vaccine,” she said. “If it’s possible to get the mammogram before your first dose, that would be great too because four to six weeks may not be enough time. The enlarged lymph nodes could last longer than that.”