The ABCs of accessory breast tissue: basic information every radiologist should know.

Abstract

Accessory breast tissue, residual breast tissue persisting from embryologic development, is found in up to 6% of the population, most commonly in the axilla along the "milk line." Radiologists should be able to recognize the imaging appearance of this normal variant on multiple modalities, while at the same time understanding that the same spectrum of pathologic processes that occur in normal breast tissue can occur in accessory breast tissue as well.