I don't know what this is, but I have it too. I have called it bone pain or muscle pain but you are correct, it doesn't go away...it just lurks there. You might ask to have your electrolytes checked, just to make sure it isn't potassium or calcium shortage.....likely it is a pain of PN, just not the tingling, burning type.

When you think about it, nerves transmit ALL kinds of pain sensation, so, why not dull and aching as well?