Hi, I am currently going through the same thing. I have a large firm growth in my upper arm. Cant be seen but felt particular when my arm is flexed. It also aches a bit. I have been referred for an urgent ct scan so awaiting that nervously.

Also anxious about sarcoma. Did they not give you any indication at your scan? 

Hi, thanks for your reply. He didn't give much away whilst having the scan only that he thought it was a lipoma but couldn't be sure. I have a history of lipomas I must have about 40 but never one like this. Hope you get your scan soon, it's such an anxious time. I've googled it till I'm cross eyed but never find much information. Good luck with your scan, do let me know how you go on.