Axillary lymphadenopathy following vaccination has long been recognized as a benign, self-limited immune response, but its increased frequency during the COVID 19 vaccination campaign created diagnostic uncertainty and contributed to delays in breast imaging and unnecessary follow-up. Early conservative guidance, issued in the context of limited evidence, led to postponed screening examinations and increased patient anxiety. Since then, robust prospective and longitudinal data have demonstrated an extremely low, near-zero risk of malignancy in asymptomatic patients with isolated ipsilateral axillary lymphadenopathy following recent COVID 19 vaccination and no suspicious breast imaging findings, even when lymphadenopathy persists for many months. In response to this evolving evidence base, the Canadian Association of Radiologists (CAR) and Breast Radiologists of Canada (BRC) have developed updated, evidence-based recommendations for the management of axillary lymphadenopathy following COVID 19 vaccination. These recommendations emphasize that breast imaging examinations should not be delayed because of vaccination, outline the importance of documenting vaccination history, and provide clear guidance for classifying and managing ipsilateral, contralateral, palpable, and persistent lymphadenopathy across breast imaging modalities. Special considerations for patients with a personal history of breast cancer or other malignancies are also addressed. Adoption of these recommendations is intended to promote consistent national practice, reduce unnecessary imaging and biopsy, support patient reassurance, and maintain the effectiveness of breast cancer screening programs.
Flegg et al. (Sat,) studied this question.