Welcome and thanks for posting your query to HCM.
In your query you have not mentioned the size of the bump and any other sign or symptoms related to this. Even then there are three possibilities of your problem:
1.Sebaceous cysts: these are due to a blockage in a sebaceous gland(produce oil in the skin).
2.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.
All these conditions are totally benign condition and not at all cancerous as you might be fearing of. All of these condition can be taken out by just 5 minutes of simple surgical excision by either a surgeon or dermatologist
. If the bump is small enough then can be even taken out by simple radiocautery or electrocautery.
You can either wait for sometime or if you feel some sign should not ignore and can meet the doctor accordingly. But last part of suggestion is to not to get panicky as all are a simple treatable conditions.
Hope to give you the best of the information.
With best health wishes,
Dr Sanjay K Kanodia
MD ( Dermatology and STD/ Venereology)