Department of Radiology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH 45229-3039, USA.
OBJECTIVE: The purpose of this study was to describe the MRI appearance of accessory breast tissue that should be considered a diagnostic possibility in peripubertal or pubertal girls who present with an axillary mass along the course of the primitive milk streak. CONCLUSION: The MRI appearance of accessory breast tissue is of a mass discontinuous with-but with signal intensity and contrast enhancement characteristics similar to-normal breast parenchyma.