Corns are a frequent problem on the foot. They are a natural response to pressure as the skin thickens up to safeguard itself from that pressure. At some stage the process goes wrong and gets so thick that it's painful. There is a continual myth that corns have roots that they can carry on growing back from when you attempt to take them out. This is like the analogy of plants which grow back from their roots if you chop the top of the plants off. That analogy continues to be applied to corns since they carry on growing back, but they do not possess roots to grow back from.
Corns develop from pressure and a competent podiatric doctor can simply eliminate a corn. The problem is that after the corn is taken away if the pressure that caused it is still there then, of course, it will come back. It comes back simply because the cause remains and not because the podiatrist left a root there for the corn to develop back from. That pressure might be from poor fitting footwear or from something like a claw toe or bunion which leads to increased pressure on an area. When the corn is under the foot, then the cause is greater pressure on the spot where the corn is, probably due to the way you walk.
The myth continues since they do return, so its important to remove the cause at the same time the corn is taken off. There is no root to be extracted. This means that the pressure on the foot the location where the corn had been has to be lowered or removed. This may involve issues like using better fitting footwear or the use of padding to get pressure off the location where the corn is. Sometimes surgery can be needed to the bone underneath the corn to remove the pressure. If that cause isn't eliminated or reduced then the corn will come back, so it's clear to understand where the myth concerning corn roots originates from.