There are several possibilities for what that could be. It could be a corn or digital keratoma (benign growth). It could be a granuloma (inflammatory tissue) that may or may not be associated with an existing foreign body (plant thorn, etc.) or bacterium. It could be a benign mass or it could be a malignancy. Your veterinarian may recommend warm compress, neosporin +/- antibiotics. If signs persist, then the mass effect can be surgically removed however it is a very sensitive area. If surgery is pursued, there will be a prolonged recovery. I just had a dog that had a similar type lesion about three months ago. While that mass came back as a malignancy, the surgical correction was curative based on the type of mass. The dog is now doing great!
btw - the pictures are well done.
I hope that that helps. I am sure the your veterinarian can get a plan and perhaps may be able to give you more information being "face to face" with the lesion.
Please let us know what your vet says.
