Lumps and Bumps on the body are common occurrences. Common ones are cysts and lipomas (fat tissue). Since you have had the lump for almost 1 year now has it grown in size or caused any symptoms?
General rule of thumb if its hard and non-mobile it maybe tethered or have a bone component to it. If its more mobile and "squishy" more likely to be a cyst. However I would recommend that you see a doctor for this for a more accurate examination.
Usually these cysts can be removed under local anesthetic and the sample/lump sent to the lab for a proper diagnosis.
Hope this clarifies.
