I mentioned thyroid because I have a thyroid cyst on my right side that no doctor noticed (I guess they just thought it was a big adam's apple?) but I found about
3 years ago. It's definitely visible and can be felt. Sometimes it aches a bit.
I've had it biopsied 3 - 4 times and it comes back non diagnostic (?!) The only thing they say they can do with it is surgically remove the whole right thyroid, and since it hasn't changed, I haven't seen any point in that.
Blood tests for my thyroid have always fallen in the "normal" range.