The atypical small acinar proliferation means that there is something that indicates that there MAY be cancer but in itself it is not a diagnostic that says it IS cancer.
AMCAR is a misspelling and is actually AMACR which is a protein test performed on suspicious lesions to detect cancer - positive means that cancer is detected but as the cell layers remain intact it implies that there is a strong chance that it is retained within the cells and hasn't broken through the cell walls.
If this were my biopsy then I would be feeling quite positive that although there is cancer present, it would seem to be early stage and that treatment should be curative.
The specialist can explain it further