I'd need - yes - no explanation needed to vote in your poll.
Let me try an analogy.
Say you have a can of Spam (not the internet kid, the meat kind), and it has a couple of peas in it. Or a pea and a kernel of corn, in your case.
In the biopsy, you walk up the side of the can and poke it with needles, pulling out core samples of what is in the needle's path. One core sample had some pea in it, and another had some corn in it.
Now you take the spam out of the can and slice it. In my case, there were 8 slices - in your case, read the report. Each slice has significant thickness. If the pea happens to be where a slice happens, it "shows up" and if the kernel of corn is between two slices, it's hidden by "spam."
Replace spam with normal prostate tissue, corn with one tumor and pea with the other, and you have "how that can happen." The post-pathology is not some sort of fussy process of slicing the whole thing whisper-thin and examining it - it's much more of a "gross" process in the not-yucky (though it probably is yucky) sense of gross. If they still have the tissue and you want to spend extra money, you could send them on a witch hunt for the kernel of corn, but I doubt your insurance will cover it.
In my case, one core of 12 had cancer (5% or 20% depending on which pathologist looked at it) but the post-pathology found multiple small tumors on both sides. Had the one needle gone slightly differently I'd have been "clean" in the sense of a negative biopsy result, but I'd still have had multiple bilateral tumors. It is not an exact science in many, many respects.
3/9 psa 2.? ••• 3/11 PSA 4.08 ••• 6/11 PSA 3.8? but Free 8%
8/11 biopsy 1 of 12 G6 (5% or 20% - depending on pathologist)
Age 47 - after much research, RALRP/w bilateral nerve sparing 10/11
Post-Path: G6 neg margins, multiple/bilateral, confined to prostate, no perineural invasion, 5%, largest 9mm
12/11 - PSA <0.1 4/12 <0.05 (different lab)
Post Edited (RandomPseudoNym) : 11/1/2012 2:53:22 PM (GMT-6)