THURSDAY, Feb. 11, 2021 (HealthDay News) — One side effect of COVID-19 vaccination is creating undue fear among women, causing them to worry that they might have breast cancer.
Both the Pfizer and Moderna vaccines can cause lymph nodes to swell, particularly those in the armpit on the side where the shot was received, experts say.
Some women are feeling these armpit lymph nodes and mistaking them for breast lumps, according to a recent report.
Further, these swollen lymph nodes can show up in a mammogram even if women can’t feel them. That prompted the Society of Breast Imaging to recommend that women postpone any mammography scheduled within four weeks after their final COVID-19 shot.
Post-vaccine lymph node swelling is common and harmless, but doctors are concerned it could cause undue fear among women. It could also trigger a false positive on a mammogram, upping the need for unnecessary further testing, said Dr. Brett Parkinson, medical director of Intermountain Medical Center Breast Care Center in Murray, Utah.
“It’s very unusual in the normal screening population to see enlarged lymph nodes. We only see it about 0.2% to 0.4% of the time,” Parkinson said.
“So when we see it, it does raise a red flag, because when that kind of lymph node swelling is present, about 50% of the time, it can represent either a metastatic breast cancer that has gone from the breast to the lymph node under the arm, or leukemia or lymphoma,” he added.
When doctors see this, they want the patient to return. “We do additional testing, usually ultrasound, and often we will do a biopsy to rule out one of those malignancies,” Parkinson said.
He noted that about 16% of clinical trial patients had enlarged lymph nodes after their second shot of the Moderna vaccine, and the Pfizer vaccine produced a similar effect.
“I actually had a palpable axillary [armpit] lymph node following my vaccination,” Parkinson said. “It happens in men as well.”
A series of case reports published online recently in the journal Clinical Imaging detailed four women who got the COVID-19 vaccine and then sought breast screening.