I'm so sorry
Did the report say the mitotic figure? That is one of the best indicators for aggressiveness.
My girl had a cluter of 5 mast cell tumors in her shoulder, but they were able to get clean margins.
Here is someone that managed their boxer's mast cell tumors with supplements, but they can be very slow growing in Boxers. http://germanshepherdhome.net/forum/...st_Cell_Tumors
I might also look at boswellia, since it is supposed to have good results for brain tumors, and in that area, you might worry about metastisis to the brain. My girl died of a brain lesion - we think it was not related, but it cannot be entirely ruled out.
Such terrible news.