Are skin cancers mostly treated by dermatologists or radiation oncologists? in Other Specialty Residencies Posted March 1, 2013 · Report reply I've never heard of Mohs surgery - is it being done in Canada? It's basically a procedure where the tumour is excised by the dermatologist who is trained as a Mohs Surgeon (requires a fellowship after dermatology residency). The dermatologist acts also as the pathologist and views all of the slides of the removed tumour to ensure that the tumour is completely resected. If there is any remaining tumour, he or she will go back to the exact location of where it remains and remove more skin. It is meant to be conservative, while ensuring complete removal of the tumour. It is definitely becoming the standard of care.