I think this is a bunionette: outside of 5th metatarsal. I will have to ask my local shoe expert to suggest a shoe with a wider toe box.
This discomfort may have been what spurred me to retie my R shoe during Sunday's marathon (too tightly, requiring a 2nd stop to retie shortly thereafter).
It's a combination of a corn plus a bunion. When I use a piece of pumice to remove the thickening skin, I don't have problems.