Nancy Cappello had annual mammograms for a decade and each time radiologists noted in their reports that she had dense breast tissue. But doctors never told Ms. Cappello, nor did they warn her that it could make her mammograms less reliable.

When her doctor found a suspicious ridge during a manual exam eight years ago, she had a mammogram and an ultrasound on the same day. The mammogram again spotted nothing amiss, but an ultrasound found a tumor the size of a quarter. Her breast cancer had also spread to 13 lymph nodes.

Read the whole story at Wall Street Journal