Can someone describe the arm pain?

alrz, LE respects no timetable--it can develop soon, later, way later, or anywhere in between.  

The pain you're experience does not sound like what I know to be my own LE pain, which is a general ache, a burning feeling, a raw-to-the-touch-irritated feeling, and periodic tingling. I've never had sharp pain, and my LE aches are not localized to one spot like you describe.  I do wonder if what you're feeling is some kind of nerve pain. I understand that when a node comes out, there's a fair bit of collateral damage in the surrounding area. I know you didn't have your surgery by a breast surgeon, but I imagine your node was removed by a general surgeon. Neither breast surgeons nor general surgeons seem to be microsurgeons who might have the ability to excise a lymph node with minimal disturbance to surrounding tissue.  I had just 5 nodes removed, and the area where I am numb at my skin is huge! That tells me that the node removal damaged nerves in a wide area.

I know you're searching for answers, and it's sure possible that lymphedema can rear its ugly head.  But I hope you'll continue to work with your care team to look for other explanations.  If your pain is from LE, there are lots of treatments that will be of no use, such as the simple use of NSAIDS. But if it's from some other source, then there may be some treatment options to pursue, so I hope you're being expansive in your search for explanations.

If anyone else around here has LE pain similar to what you describe, I'm sure she will speak up.  One thing is certain about LE:  nothing is certain!  My aches and discomforts may be quite different from everyone else's.

I'm so sorry you're dealing with such frustration.

Carol