Shaving and Excision are both unique procedures in regards how they remove a lesion. Each type has a unique approach when it comes to doing it.
If your documentation for the procedure supports shaving, then it will be coded to that, and if you look how the shaving procedure works, it pretty much includes an excision. So the diagnosis should not change your approach on the type of procedure performed. Excision and shaving they both required different techniques so code the procedure to what its supported.
Hope this helps!