How do you approach a breast cancer patient with outside pathology returning as HER2 positive on FISH but internal pathology review showing conflicting results and HER2 negative on FISH on same sample?

I will give some thoughts but appreciate other opinions as well. First, it is important to consider the labs performing the assessment and their level of comfort/expertise in this assay (i.e. which do you trust).

Next, it's important to recognize that especially in borderline cases of Her2 positivity...