One of the side effects of the COVID vaccine can be enlargement of the lymph nodes under the arm into which the dose was injected. Over a period of time, those nodes will return to normal size and any soft tissue swelling will resolve.
Enlarged nodes may be a normal response to the vaccination. Our breast imaging program is aware of this side effect and will follow Society of Breast Imaging recommended guidelines to ensure patients are safe.
So as not to confuse the swelling with a more serious condition, Midstate Radiology Associates have taken the following actions:
- Technologists screen all patients for recent COVID-19 vaccination, noting date and site of injection.
- If our radiologist finds enlarged nodes on imaging they will further investigate with ultrasound.
- A short interval follow-up ultrasound in 2 to 3 months may be recommended to confirm resolution of findings (confirm that nodes have returned to normal size).
MRA representatives will ask if you have had a COVID vaccination or have an appointment for your vaccination:
- It is recommended that screening breast imaging (mammogram, ultrasound or MRI) be performed before the vaccination, or 4-6 weeks following vaccination.
- It is NOT recommended to postpone routine screening any longer than 4-6 weeks as more serious conditions can also present with enlarged lymph nodes (adenopathy).
- If there are symptoms related to the breast, such as pain, skin changes, nipple discharge or a palpable lump, imaging should NOT be delayed.
Do Not Delay Diagnostic Breast Imaging
COVID-19 Vaccination Lymphadenopathy and Breast Imaging FAQs
1. What is lymphadenopathy?
Axillary lymphadenopathy is swelling of the glands or lymph nodes in the armpit region.
2. Why is axillary lymphadenopathy a concern now?
Axillary adenopathy has been reported with the administration of both Pfizer and Moderna COVID vaccinations. Patients may experience swelling or tenderness, or there may be a visible finding on a screening mammogram.
It is important to note that vaccines of all types can result in temporary swelling of lymph nodes, a sign that the body is mounting a normal response to vaccination by making antibodies – a good thing!
3. How often is axillary lymphadenopathy reported after vaccination for COVID-19?
In clinical trials of the COVID vaccines, up to 11% of patients reported axillary tenderness or swelling after the first vaccine dose, 16% after the second dose. This preliminary data may be revised as more people are vaccinated.
4. If we know axillary lymphadenopathy is a side effect of the COVID vaccination, why could this be a concern?
There are other reasons for swollen lymph nodes under the arm. Infection or inflammation can result in adenopathy. Less commonly, breast cancer, lymphoma or other malignancy can present with lymph node swelling.
Any reported pain, lump, swelling or other issue reported by a patient when presenting for a screening mammogram will prompt diagnostic imaging for further evaluation. A screening mammogram is preventative only.
5. What steps are being taken to provide accurate information regarding the vaccination?
Both our schedulers and technologists ask patients if they have had the COVID-19 vaccination, as well as when and where (left vs. right arm) the vaccine was administered. This information is provided to the radiologists.
Enlarged lymph nodes on screening mammography will require further diagnostic assessment, most likely with ultrasound. A short term follow up imaging study may be recommended to ensure adenopathy has resolved. Should lymph node enlargement persist at follow-up, then additional evaluation may be recommended, including biopsy.
If a patient has a screening mammogram scheduled within one month following COVID-19 vaccination, she will be offered the opportunity to delay that imaging by 4 to 6 weeks, allowing time for any vaccine-related lymph node swelling to resolve.
6. Does a patent have to postpone their screening breast imaging appointment?
It is not mandatory to postpone screening breast imaging for 4-6 weeks, it is an option for those patients who would prefer to do so.
7. If a patient experiences breast or axillary pain after the vaccination, should they ignore the pain and wait 4-6 weeks?
Patients should not ignore pain in or near their breast tissue. They should report pain to their physician, who will guide them to the next appropriate step. We don’t want to ignore potential problems because of this side effect, but also don’t want to alarm patients or perform unnecessary imaging or biopsies if not warranted.
For additional vaccine information, please visit the Hartford HealthCare website.