I've got what feels like a cluster of hard lumps (2 or 3?) under my arm. I know that many things could cause these, but I'm particularly worried because they are in an area in which changes have occurred over the past six months or so. This is hard to describe, but it's a noticable (I can see it in the mirror) "pooch" in this area, a different contour that wasn't there before and that is unilateral. Previously, I didn't detect any lumps within the "pooch", but now I do.

I'm 44, female, with a history of a hurthle cell ademoma of the thyroid but no other health problems.

Can anyone give me any insight?

Many thanks!