What Causes Severe Pain And Weakness Post Neurothekeoma Tumor Removal?

Hi, I have a history of Neurothekeoma from several years ago and the tumor was excised. I am currently having severe pain in the same extremity and same general area, weakness, and decreased motion. There are times when the pain is almost unbearable. I have been tested for Rheumatoid Arthritis and it was negative. Do you have any suggestions for me?