The mammary ridge—A case report of multiple ectopic breast masses

Ectopic or accessory breasts describe residual breast tissue that fails to regress during normal embryologic development anywhere outside the expected locations. Ectopic breast tissue is seen in 2–6% of the population and is categorized into two types: supernumerary and aberrant breast tissue. The extent of development of this accessory tissue varies from rudimentary to complete with organized glandular and ductal development. Given this, it is possible for the same pathology that affects normally positioned breast tissue to also affect accessory breast tissue.