Why are the lymph nodes enlarged after the administration of the anti-coronavirus vaccine?

, medical expert
Last reviewed: 04.09.2021

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30 April 2021, 09:00

An enlarged axillary lymph node is a common symptom that occurs after vaccination against coronavirus infection. Experts pay attention that this consequence is not a complication, but should be perceived as a variant of the normal course of the process (provided that the patient does not have any other pathological changes in the mammary glands). Similar medical recommendations were published in the famous American Journal of Radiologists AJR.

A team of scientists from the University of California Los Angeles has carefully examined digital medical records of patients who have recently received the anti- coronavirus vaccines Moderna and Pfizer / BioNTech. All women underwent mammological diagnostics during the experimental period, during which the size, configuration and density of axillary lymph nodes were determined. Additionally, ultrasound and magnetic resonance imaging were performed .

As a result of the experiment, an increase in axillary lymph nodes was found in more than 20 women of different age categories - from 28 to 70 years. Experts note that lymphadenopathy was detected according to the ipsilateral principle from the side of vaccination. At the same time, 13% of patients voiced complaints of uncomfortable sensations in the axillary area and mammary gland (pulling pain, feeling of pressure and tissue compaction). And the rest of the women showed no unpleasant signs: they learned about lymphadenopathy only in the process of diagnosis or control studies.

The time interval between the introduction of the first dose of the anti-coronavirus vaccine and the detection of enlarged lymph nodes was several days (on average, from two days to four weeks). Most of the women (more than half of them) had only one pathologically enlarged lymph node.

Based on the results of the examination of the mammary glands, the specialists applied a description of the revealed changes and their assessment using the Bi-RADS system (a system for interpreting and recording breast diagnostics). One patient was classified as Bi-RADS 2 (only benign changes were detected), 21 women were classified as Bi-RADS 3 (mostly benign changes with a recommendation to retest for 4-24 weeks). One woman was assigned a Bi-RADS 4 (suspected malignant process) category with a history of previous breast cancer. As a result of a biopsy, this patient was diagnosed with a reactive form of lymphoid hyperplasia.

Experts explain: an increase in the axillary lymph nodes from the side of the vaccine administration against the background of the absence of other pathological changes in the mammary glands can be described as a temporary response of the body. It is important that this reaction is correctly interpreted by the doctor, because in this case, the appointment of a biopsy would be unreasonable.

Primary Source of Information:  AJR Radiographers Journal

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