What Could A Painful Thigh Lump With Hardness Be?

My husband met with an accident an year ago. A car had hit him on his left thigh and he was on bed rest for fifteen days. Although he had no fractures or any severe injuries. Now the area which was hit i.e. His left thigh, a lump has formed over there. It is not generally painful but has slight pain sometimes. The skin underneath has become very hard. He is too afraid to consult a doctor because he thinks doctor will ask to operate it. Can you pls suggest what it could be?