Suggest Treatment For Soreness In The Left Armpit Area

Question: I sneezed very hard almost 1 yr ago. And knew right after the sneeze that I had seriously tore some muscles on my left. With severe pain right up to and including my left armpit. The pain subsided in my left rib area
After a while. But it is still very sore and tender in left armpit area and. somewhat swollen The lymph nodes are in that area and appear swollen as well. I have had renal cell carcinoma. With several metastatic visits to other organs. Of course since it appears that lymph nodes are involved I am very concerned because of my
History with renal cell carcinoma I had a very recent left chest X-ray and it did not indicate anything but
The doctor suggested a pet scan or MRI. Is it possible that the severe muscle tear is still causing all this pain 12 months later And would it or could it inflame or irritate the lymph nodes. I will follow up with my oncologist within 2 weeks. But I do not know what type of doctor to see if this is Not cancer related
Perhaps I need physical therapy. I'm lost and confused but I want to find out what is causing this pain
And what can I do to help it get better. Pls advise
Thx XXXX. YYYY@YYYY

What is FNAC. ????