Actor Mark Wahlberg talks openly about his third nipple—and doesn’t hide it onscreen. How common is it to have an extra nipple, and is it a problem?
Extra nipples actually are pretty common. Medically called supernumerary nipples, it is estimated that they are found in 10% of people in the US. If that high number of extra nipples surprises you, it’s probably because they generally are small enough that you might have seen them on many people but mistaken them for moles. Recorded cases of extra nipples date back to the Roman empire and include well-known people—Anne Boleyn, for instance. More recently, country music singer Carrie Underwood, actress Tilda Swinton and, as mentioned, Mark Wahlberg are among the members of the extra-nipple club. While Wahlberg is open about his extra nipple, it wasn’t always wise to admit having one. In Boleyn’s day, it might have gotten you labeled a witch. Today, however, supernumerary nipples are merely a curiosity, thought of as, say, a harmless birthmark would be and not an indication of an underlying medical condition (or of supernatural powers). Nipples form naturally at an early stage of fetal development along a ridge of skin called the “milk line” that stretches from the armpits to the groin. Breast and nipple glands form most of the time only on the chest, and then the rest of the ridge disappears. Occasionally, though, other spots along the milk line develop into extra nipples—or even breasts, complete with breast tissue glands and areolas (the colored part around the nipple). Supernumerary nipples appear more often in men than women. While the nipples are not hereditary, in some cases they have appeared in several generations of a family. Most supernumerary nipples look like moles or birthmarks—they’re brown or flesh-colored and smaller than regular nipples. (Wahlberg describes his as being the size of “an infant’s nipple.”) Usually, they show up right below the breasts, but they’ve also been found on the back or the neck where they’re called ectopic, or abnormally placed, supernumerary nipples. Some supernumerary nipples act like regular breast tissue. They can grow and become more noticeable during puberty for both men and women...and on women, they can become tender and sore before a menstrual period…and even produce milk after childbirth. While there is no medical reason to remove a supernumerary nipple, if one is bothersome for cosmetic reasons, removal is a simple outpatient surgical procedure that is similar to having a mole removed. In fact, Carrie Underwood had hers taken off. Some doctors refer patients to a plastic surgeon to do the procedure, which takes about an hour and requires only local anesthesia, but some do it themselves. Bottom line? Humans can and do come into this world with all sorts of “extra parts”—fingers, toes, teeth, ribs, kidneys, spleens and uteruses, to name a few. Tumors called teratomas, containing hair, teeth and bones, have been found inside uteruses. All things considered, an extra nipple isn’t much of an oddity—and certainly not anything to worry about!