Doctors recommend women wait to schedule their screening mammograms until six weeks after their second dose.By Dr. Maria Simbra

PITTSBURGH (KDKA) — After a mammogram, Allegheny Health Network Director of Breast Imaging Dr. Adam Fang had to call a patient because of something that looked like cancer.

“I actually called somebody back who had an enlarged lymph node,” said Dr. Fang.

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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 with the COVID shot — 11 percent of people after the first dose and 16 percent after the second dose with Moderna vaccine.

“That’s just your body reacting the way it should,” says Dr. Fang. “I can say, personally, that I had enlarged lymph nodes on that side and in my neck. So it does happen. I got the Pfizer and had that happen.”

(Photo Credit: KDKA)

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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.

“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’s most likely going to be related to the vaccination,” Dr. Fang said.

Because of this issue, doctors are recommending that women wait to schedule their screening mammograms until six weeks after their second dose. Diagnostic mammograms for a lump, pain or discharge should not be delayed.

“We don’t want to scare people unnecessarily,” he said.

This allows the swelling to decrease on its own. If the lymph node remains enlarged, the doctor may proceed with a biopsy.

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At AHN mammogram centers, the appointment questionnaires now include dates of coronavirus 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.