Welcome and thanks for posting your query to HCM.
After reading your problem there are possibilities of your problem:
1.Lipoma:A simple fatty tissue growth beneath the skin. It is painless, soft, movable lump.
cysts: It is an overgrowth of normal tissue in an abnormal location.
3.Sebaceous cysts: these are due to a blockage in a sebaceous gland(produce oil in the skin).
All of the above conditions are totally benign condition. The reason for numbness
and pulsatile nature might be due to the location of the lump over nerve
respectively, giving compression on these structure.
The most important suggestion is that a bump on head of any kind should never be ignored (whether small or large). You should meet a surgeon who can help you out in diagnosing the condition at his best.
Hope to give you the best of the information.
With best health wishes,
Dr Sanjay K Kanodia
MD ( Dermatology and STD/ Venereology)