Thanks for the PM!
These lesions are not that uncommon. Unfortunately when the nasal planum and adjacent skin have severe inflammation the areas will look the same regardless of the underlying cause. Thus a fungal infection, bacteria, DLE, pemphigous, tumor, etc. can all look the same. So the key is a methodical workup with fungal and bacterial culture, followed by 4 week course of antibiotics, and then biopsy. If a biopsy is performed, it should be submitted to a dermal histopathologist which is a subspecialty. Often in the course of the workup, blood testing may be recommended to rule out underlying disorders like Cushing's disease or hypothyroid which may predispose the pet to a bacterial or fungal infection.
And to help you feel better, a tumor (that is cancer) is much less likely. I would focus on infectious or immune mediated disorders. We have to include tumors but based upon the photos, I think that cancer is unlikely.
Again, hope it helps.
