As I cannot examine you, I cannot tell you what this is. However, the scalp is a common place for a variety of cysts and solid lesions (thankfully, most of them are benign).
You should ask your doctor to have a look at this area of your scalp.
Sincerely/ Robert A. Wascher, MD, FACS
www.doctorwascher.com
www.oncoguard.com