Disney had one that looked very similar to that on the side of her head around her temple. It was removed and biopsy and was benign. Since then she's had a few more, always benign. The last one was about three years ago. Now she has lots of moles or wart-like places all over her and the vet said they are common in older white dogs and are also benign.

Good luck Harley, prayers on the way.