Rob1 Did you have any drains in place following surgery? Or have you had any medical people (breast care nurse, community nurse, surgeon, GP) look at your wound after surgery?
I originally had 4 lymph nodes removed with a lumpectomy. That caused a small 1-2cm lump under my armpit which I had checked out by my GP then my surgeon. They determined it was a lymph node dealing with the removal of its friends. A week later it reduced in size and settled down.
I then had 6 more lymph nodes removed through an incision under my arm pit. I was sent home with two drains which stayed in place for less than a week to collect fluid. I had some general swelling across the breast and armpit but nothing particularly hard or resembling a tennis ball. Paracetamol was enough to help with pain and weird sensations that then started to develop as the healing continued.
I saw my surgeon two weeks after my surgery and he checked how I was healing.
Both surgeries took a while to heal, the second took longer. I was given a booklet of exercises by the breast care nurse that helped recover movement in the arm.
Three months since the second surgery, I've had full movement in my arm for a few months but there is a little tightness with certain movements so I'm still doing exercises and noticing improvements. There are still some weird sensations (or lack of) under my upper arm.