A supernumerary nipple presents as a small, brown- or pearl-colored macule, or as a concave spot, and is usually located just within the areola of normal breast tissue, and in this rare circumstance the problem is believed to be due to intrauterine dichotomy of the developing nipple.
The accessory nipple can be present with or without the areola, and vice-versa. A supernumerary nipple can be located appear along the two vertical “milk lines,” which start in the armpit on each side, run down through the typical nipples and end at the groin. They are classified into eight levels of completeness from a simple patch of hair to a milk-bearing breast in miniature. The presence of a supernumerary nipple in an atypical location, such as the neck, arm, leg, buttock, shoulder, scapula, spine, vulva, or perineum is rare. Breast tissue is occasionally present beneath the nipple.
Treatment for Supernumerary Nipple is not usually required as they are harmless, but for cosmetic purpose if it feels embarrassing then it can be removed surgically. It can be corrected in one surgery as an outpatient procedure and surgery time is about 1 hour, and can be performed under local anesthesia, much like having a mole removed. If it is seen early in infancy or neonatal period, it is suggested to wait till the patient reaches puberty rather than going for surgery, sometimes it can be less visible later. But if there are any changes in color or size you have to inform to your doctor immediately. Sometimes they may grow as a regular nipple or breast. In few cases, this could be associated with melamona, carcinoma, fibroadenoma, or Paget disease.