This is Dr. Rahul Nagar, a consultant Dermatologist
in New Delhi, India. Sebaceous cyst
is a very common and completely benign growth which doesn't require any treatment most of the times.
Removal may be advised if it is cosmetically disfiguring, becomes painful, inflammation, infection, if the diagnosis is doubtful, etc.
However, a lesion on scalp
is most likely to be a sebaceous cyst.
Do not worry at all. It surely is benign. Such cysts usually contain toothpaste like material but may be empty as well.
Take care. Hope this helps you.