Is it called arm lift too??
 

I have a problem! I'm a girl and I have muscular arms that makes me look like a man ( only the arms, \not the shoulders) and I wanna know if it exists a cosmetic surgery that can make my arms look smooth just like girls and how much it costs.
It really important to me . Thank you!! :)

Yes, You can
 

Yes, You can go for Brachioplasty (Arm Lif Surgery).

But, you haven't mentioned your age, if you are a teenager, I suggest you to wait for some time since your body is growing.