I have a tabby that has this strange nose thing.?

its like boogers that he never cleans,and when I clean them they just come back in like 10hours or so. Does anyone know what this is? I had one vet say don't worry about it and one said that is was a cancer that cats get. It like slowly eats away the face of the cat. Now I have had this cat for about a year and nothing has appered like that. Is it somthing that I should worrry about or is it just nothing?