Two bumps/lumps on top of both feet out of nowhere, what is this?

Have it evaluated: Some reasons that one may develop a callus include: friction, pressure, repetitive trauma, and a limitation of joint motion. Some genetic conditions may also cause people to develop calluses on the hands and the feet. Other conditions such as warts which result from a viral infection may be confused with calluses. Treatment depends on the cause of the problem. Have it evaluated by a professional.

See doctor: For an evaluation as there are many causes and this cannot be diagnosed over the internet, make sure shoes are properly fitted.