Coronavirus Vaccine Side Effects Could Interfere With Mammogram Results, Doctors Say

When lymph nodes swell, they can look just like cancer. KDKA's Dr. Maria Simbra has more on why doctors are sharing a new set of advice.

Video Transcript

- It may be important to space your coronavirus vaccine and your mammogram several weeks apart on your calendar.

- As Dr. Maria Simbra reports, the vaccine could actually affect what doctors see on the screening.

MARIA SIMBRA: After a mammogram, Dr. Adam Fang had to call a patient because of something that looked like cancer.

ADAM FANG: Actually called somebody back who had an enlarged lymph node.

MARIA SIMBRA: Turns out, she had received her COVID-19 vaccine three days earlier. While swelling of the lymph nodes under the arm on the same side as the shot can happen with any vaccine, it happens more often with the COVID shot-- 11% of people after the first dose and 16% after the second dose with Moderna.

ADAM FANG: That's just her body reacting the way it should. I can say personally that I had enlarged lymph nodes on that side and in my neck. So it does happen. But I got the Pfizer and I had that happen.

MARIA SIMBRA: Lymph nodes are small bean-shaped structures throughout the body as part of the immune system. When they swell, they can look just like cancer, so doctors will have a patient come back for more tests.

ADAM FANG: We don't know that it's not related to cancer. So we don't want to miss the opportunity to catch something even though it most likely is going to be related to the vaccination.

MARIA SIMBRA: Because of this issue, doctors are recommending that women wait to schedule their screening mammograms until six weeks after their second dose.

ADAM FANG: We don't want to scare people unnecessarily.

MARIA SIMBRA: This allows the swelling to decrease on its own. If the lymph node remains enlarged, the doctor may proceed with a biopsy. At AHN Mammogram Centers, the appointment questionnaires now include dates of COVID vaccine doses and which arm. If you're too close to your immunization, you will have the option to reschedule. If you'd like to proceed knowing that you might have to come back, you may. They will not turn you away. I'm Dr. Maria Simbra, KDKA News.