Thanks for writing to us.
The hard bony lump is likely to be due to fibrosis
in the area of haematoma
formation. You need not worry as it is a part of the natural healing process. The swelling will resolve on its own without any treatment in few months.
I hope this information has been both informative and helpful for you. You can consult me again directly through my profile URL http://bit.ly/Dr-Praveen-Tayal
Dr. Praveen Tayal