Black lumps under skin?

[confuseddotcodotuk]

Yesterday I noticed my friend had black lumps under his skin on his chest area (below his right nipple). He hadn't even realised they were there and isn't bothered about them but I am a bit worried! There were a few scattered in that area, I can't remember how many but more than 4, a couple were pea-sized and the others were smaller and they were just hard, black, spherical lumps under the skin.

I'm googling but can't seem to find anything solid, only one forum where a bunch of people mentioned finding only one on them and squeezing it and out pops a black stone-like thing, which sounds about right, but haven't been able to find a pic or anything to compare it too and no mention of having a cluster of them?

Any ideas what it could be?

And I did think of ingrowing hairs as he is a bit of a hairy bugger () but I'm used to those and this looks completely different!

My DH has one of these on his shoulder. unfortunately he won't let me squeeze it to find out what's inside but it's been there doing no harm (AFAIK) for as long as he can remember. Will be watching this thread to see if you get any answers!

(BTW was there a PICTURE of the squeezing???)

No pics, which is what I've been trying to find as it's easier to tell from pics iyswim? I did get linked to a youtube video of a massive blackhead being squeezed, I was morbidly fascinated by that and a few others on there! But nothing that looks similar. I'm fascinated by this stuff, I wanted to be a dermatologist when I was younger and wish I did go down that route now

I've never seen anything like it, but was speaking about it with him this evening and he's still not fussed about them what-so-ever, we had a good look and poke and they don't hurt him or anything but they are noticeable.