According to Wikipedia:
Accessory
bréasts, also known as polymastia, supernumerary bréasts, multiple chest
syndrome, or mammae érraticae, is the condition of having
additional bréasts. Extra bréasts may appear with or
without bósoms or areolae. It is a condition and a form
of atavism which is most prevalént in male humans, and often goes
untreated as it is mostly harmless. In recent years, many affected women have
had a plastic surgery operation to remove the additional bréasts, for
purely aésthetic reasons.
Credits to Talkofnaija.com
