Can I live forever with benign osteoma in my skull?

When I was 15 years old, I recognized one small tumor at the right site of my head. When I grew up, it grew with me. Until I was 22-24 years old, it was kept unchanged (1/3 of an chicken egg in size).
Yesterday, I went to hospital to check with X-ray and CT scanner. Doctor said I have a benign osteoma and I should have an operation to remove it.
I' ve been living with that osteoma for over 10 years; can I continue my life with that osteoma without doing operation? What can be occurred without removal of the osteoma? I am really scared of operation, especially in my head. Is this operation an easy and safe operation? What can happen if I have to use an artificial bone (the Doctor said patients have to use artificial bone if an osteoma related to bone must be cut)? I am really worried about that. How long can I recover after the operation? Now, I have just 42 kg with 162 cm in height. Can I have the operation without loosing my weight?

Many thanks for your answers!