COVID-19 vaccine side effect causing false positive cancer screenings - KHOU.com

According to MD Anderson Cancer Center, that swelling is causing false positives on cancer screening exams.

"Cancer experts at MD Anderson are seeing an uptick in mammograms identifying a false positive for breast cancer due to a common side effect of the available COVID-19 vaccines — swollen lymph nodes.

The detection of swollen lymph nodes in imaging exams has led to false positives for leukemia and lymphoma patients, as well," MD Anderson said in a release.