Coronavirus vaccinations can cause enlarged lymph nodes in the armpit or near the collarbone, which may be mistaken for a sign of cancer.
As vaccines roll out across the country, doctors are seeing more and more of these swollen lumps in recently vaccinated people, and medical journals have started publishing reports aimed at reducing anxiety and helping patients avoid unnecessary testing for a harmless condition that will go away a couple of weeks.
The swelling is a normal immune system response to the vaccine and occurs on the same side as the arm the shot was fired on. It can also occur after other vaccinations, including those for the flu and human papillomavirus (HPV). Patients may or may not notice it. However, the enlarged lymph nodes appear as white spots on mammograms and breast scans and are similar to images that may indicate the spread of cancer through a tumor in the breast or elsewhere in the body.
“I make special efforts to inform all patients who are being monitored after successful previous cancer treatment,” said Dr. Constance D. Lehman, an author of two Magazine article on the problem and the chief of breast imaging at Massachusetts General Hospital. “I can’t imagine the fear of getting the scan and hearing.” We found a knot that is big. We don’t think it’s cancer, but we can’t say, or worse, “We think it might be cancer.”
The armpit swelling was a recognized side effect in the large studies of the Moderna and Pfizer-BioNTech vaccines. In the Moderna study, 11.6 percent of patients reported swollen lymph nodes after the first dose and 16 percent after the second dose. Pfizer-BioNTech appeared to have a lower incidence, with 0.3 percent of patients reporting it. However, these numbers only reflect what patients and their doctors have noticed, and radiologists say the real rate is likely higher and that there are likely to be many more cases in imaging such as mammograms, M.R.I.s, or CT scans.
The condition was not listed among the reported side effects in a briefing document from the Food and Drug Administration on the Johnson & Johnson Covid vaccine. On Saturday the agency approved the company’s emergency vaccine.
Dr. Lehman said it was important for imaging centers to ask patients if they received Covid vaccinations and to record the date of the shot and the arm it was placed in.
Your clinic includes this notice in a letter to patients whose screening reveals swelling but no other abnormalities: “The lymph nodes in your armpit area that we see on your mammogram are on the page where you got your last Covid-19 vaccine got bigger. Enlarged lymph nodes are common after the Covid-19 vaccine and are your body’s normal response to the vaccine. However, if you feel a lump in your armpit that lasts more than six weeks after your vaccination, you should tell your doctor. “
One way to avoid the problem is to postpone routine mammograms and other imaging tests for at least six weeks after the last dose of vaccine an article by a panel of experts in the journal Radiology published Wednesday.
A professional group that Breast Imaging Societyoffers similar advice: “If possible and if care is not unduly delayed, schedule screening exams before the first dose of Covid-19 vaccination or 4 to 6 weeks after the second dose of Covid-19 vaccination.”
However, the panel of experts also warned that non-routine imaging, which is needed to treat a disease or other symptoms that could suggest cancer, should not be delayed. Immunization should also not take place.
People with cancer are generally recommended to get vaccinated against the coronavirus, especially because they are at a higher risk of dying from Covid than the general population. However, some cancer treatments can affect the body’s ability to fully respond to the vaccine The American Cancer Society advises patients Consult with your oncologist about vaccinations.
Recently vaccinated people who have cancer and develop enlarged lymph nodes may need additional tests, including a biopsy of the nodes, said Dr. Lehman.
She described a patient with a newly diagnosed breast tumor who had swollen lymph nodes on the same side and who had recently received a Covid shot in the arm on that side.
A biopsy was performed, an important step to determine if there were any malignant cells in the nodes, which would then help determine a course of treatment. It was negative for cancer. The vaccine most likely caused the swelling.
In another case, a woman who previously had cancer of the right breast had a routine mammogram that showed an enlarged lymph node in her left armpit and no other abnormality. She recently had a Covid vaccination on her left arm. Doctors found that no further testing would be needed if the swollen lumps did not last more than six weeks.
In a man with a history of bone cancer, a follow-up chest CT scan found swollen lymph nodes in one armpit – on the side where he had recently received a Covid vaccination. Nothing else was wrong and no further testing was required. The same decision was made for similar findings in a recently vaccinated man who had a chest CT scan to screen for lung cancer and in a woman with a history of melanoma.
For patients undergoing cancer treatment in one breast, the Covid shot should be given in the arm on the other side, said Dr. Lehman. The vaccine can also be injected into the thigh to avoid problems with lymph node swelling.
“This could really affect a lot of people if we don’t get vaccination status straight away in imaging centers,” said Dr. Lehman. “I also want cancer patients to know that they can get the vaccine on the opposite side or even on the leg to avoid confusion.”