After 5 weeks, 4 doctors, 3 x rays, and 1 MRI, the results are in. They are determining my injury a "stress reaction". Basically, the radiologist and 2 foot specialists reviewed the MRI and couldn't find an exact fracture site, just an area in the 4th and 5th metatarsals that had some edema, inflammation, and trauma. If I continued running on it, eventually I would have a fracture in the bone.
I'm supposed to stay off my foot for a week or so, and use crutches or a walking boot. It could take 6 days to heal, it could take 6 months to heal. I'm allowed, and encouraged, to cross train. Then, when I don't have pain walking in my normal shoes for a week or so, I can slowly start adding in running.
The foot specialist says he doesn't know what caused it. I would love to know the reason so I know how to prevent it in the future. Since my training has been legit (NOT too much, too soon) and my diet is healthy and well-balanced, the dr speculates that when I had the pain in the ball of my foot, I may have altered my gait. This may have put undue stress on the outside of my foot, hence my 4th and 5th metatarsals.
It is encouraging that there isn't a broken bone. Which means it should heal faster than a normal stress fracture (6 weeks). I've also been running for 33.5 years without ANY type of foot pain or injury. Hopefully this is a one-time fluke and not a regular occurrence.
As previously stated, the doctors and myself don't really know exactly what "this" is, and what caused it. Therefore, it's hard to prevent it from happening again.