Brown spot on bottom of foot, what is this?

Pigmented lesions: Any new pigmented skin lesion anywhere on your foot should be looked at by your podiatrist or dermatologist to see if a biopsy is needed. If the brown spot has been there for many years time without any changes, it is probably benign. However, your podiatrist or dermatologist should evaluate this at some point anyway.

MELANOMA: This should be seen soon by a podiatrist or dematologist, to make sure it is not a melanoma, which is a serious cancer. Again, I'm not saying it is, but it must be ruled out. Regards, Dr. Latva