So, is this a mutation?

July 22, 2009 1:44 AM

Weird question, I'm sure.... How do you know if a skin growth is a mole or if it is a supernumary nipple? It LOOKS like a (small) nipple, no areola, and is in line with where a third nipple would likely be....but it could just be a mole...is there some sort of definitive way of knowing the difference?
posted by polexxia to health & fitness (6 answers total)

It's almost impossible to tell without a biopsy to look at the tissue underneath; basically you'd need to check whether it has a milk-producing gland underneath. Unless you start lactating naturally, in which case an extra nipple will swell and in some cases actually lactate.

Extra nipples are actually remarkably common. At a conference a while ago I heard a speaker (an expert on breast tissue development) give the figure as about 1/12 people, although most assume it's a mole. They're usually found on the "nipple lines", the vertical lines down the chest where you'd expect to have extra nipples if you were a half-cat, half-human hybrid. It's very rare for the extra ones to have an areola.

The talk was actually really cool. He was a breast cancer researcher and was researching how normal breast tissue develops, to give an insight into how and why cancerous breast tissue develops. One of his discoveries was that you can persuade a nipple to form by creating a local high concentration of a certain growth hormone. He soaked plastic beads in this stuff and inserted them under the skin of mice, which made them grow a new and apparently normal new nipple at the bead location. The hope was to use this technique to give human mastectomy patients a new nipple to replace the one they'd lost, both for appearance (important in dealing with the psychological aftermath of mastectomy) and, possibly, allowing those women to breast feed.
posted by metaBugs at 2:22 AM on July 22, 2009 [5 favorites]

Also: I'm a biologist but not a doctor. If you're worried for any reason (e.g. feel a new lump underneath, notice changes in size or colour, notice soreness etc) you should talk to your doctor.

And... er... could a friendly mod delete my first reply? I thought I pressed "stop" before it sent, but it seems I was too slow.
posted by metaBugs at 2:31 AM on July 22, 2009

I had a growth on a nipple line. I had it removed. Jokingly I asked if it were a third nipple. I learned from the biopsy that yes, they can tell you exactly what type of tissue it is. Mine was not. Just a plain old, nipply-looking mole.
posted by FergieBelle at 11:35 AM on July 22, 2009

I have a small, flat spare nipple, about half the diameter of a pencil eraser. I know it's not just a mole because if I poke it, or rub an ice cube on it, it draws up a bit, and I assume if it were larger it would get hard and poke out like a regular nipple. It's also the exact same colour as my other nipples. I've had it my whole life, but I didn't realise it wasn't just a mole until an ex pointed out the amazing similarities in colour ,texture, and erectile response between the spare and the other two nipples. After that discovery he would occasionally referred to me as Eccentrica Gallumbits ( the Triple Breasted Whore of Eroticon 6 from the Hitchiker's Guide - unfortunately unlike the actual Eccentrica, my erogenous zones don't start several miles away from my actual body. Shame),
Anyway, point of story, if you don't want to have it removed to see what's underneath, maybe rub an ice cube on it and see what happens?
posted by Wroksie at 12:27 PM on July 22, 2009

This is easy.
Are you or are you not a witch?
posted by Lou Stuells at 4:20 PM on July 22, 2009

IANAD, but from a little googling, it appears that an extra nipple appears on the milk line (or, in medical lingo, mammary ridge) that runs from the base of the arm (armpit, or axilla) to the base of the leg (groin). It is located there because, in the developing embryo, there is tissue along this line from which nipples develop. So, if a suspected extra nipple isn't on that line, then chances are it isn't one.
posted by exphysicist345 at 10:39 PM on July 22, 2009