Is it normal feel numbness and weakness in the arm, shoulder,neck and lower back after Lipoma removal 4 mos. ago. (photo)

4 months ago, I undergo a surgery to remove a lipoma on my right upper back,near the scapula side.Histopath results show its a Lipoma. Wounds Completely healed.But Right now Im starting to feel numbness and weakness in my right arm, radiating in my shoulder, neck and lower back right side. Is it normal to feel like this? Im worried that maybe its progressing to a malignant type. after all I read about Liposarcoma. thank you