Reactive Lymphadenopathy: Triggering False Positives on Magnetic Resonance Imaging

There are numerous etiologies of reactive lymphadenopathy on radiological imaging. Lymph node evaluation is critical for screening high risk patients for new pathology, and for the planning of systemic chemotherapy and radiation therapy. Although ultrasonography (US) is useful for screening and staging illness, it is not completely reliable. In addition to being subjective, there is also poor accessibility of deeply located lymph nodes. Breast Magnetic Resonance Imaging (MRI) offers the advantages of provision of a larger field of view, increased capability of comparison of right and left axillary areas, and increased sensitivity and specificity. It is reported that pandemic H1N1v and seasonal influenza vaccinations cause alteration in fluorodeoxyglucose avidity in positron emission tomography (PET)/CT scans. There were no identified scientific publications documenting the possibility of false positives on MRI due to the Shingrix vaccine, nor any universal recommendations for patients to avoid vaccinations for a specified period of time prior to imaging. The following is a case report of false positive reactive lymphadenopathy found in a healthy patient during breast MRI screening due to high risk status.