Hi,
For what it's worth, I've been told that a lesion can be viewed different ways. That is why when you get a second opinion from a different cancer center (or more) they always insist on seeing your slides so their pathology dept. can have a go at it. I had mine viewed as moderately well diff. & well diff. (from one place), Then it was labeled "superficially invasive" by another, and then I was faced with a metastasis to a lymph node, called met. rather than reoccurence because it happened within about a month of the biopsy excision! My last stop called it "moderately well", and the lymph node a met. because there was no cancer left in my tongue when they recut. I am no expert, but I would say that judging the histology of the lesion is at least partly the decision/view of the particular pathologist. I am also sure that they try to quantify it as best they can to take some of the opinion of out it. (there's hedging an opinion for you)
Anne