<p>A) Negative to weak cytoplasmic staining in normal ductal epithelium (white arrows). B) Moderate staining (mostly cytoplasmic) in normal ducts adjacent to tumor (white arrows). C) Moderate to strong staining in a normal centroacinar and small ductal cells (white arrows); D) Weak staining in a ductal adenocarcinoma (black arrows); E) Strong staining in a well differentiated ductal adenocarcinom (black arrows); and F) strong staining (mostly nuclear) in a poorly differentiated ductal adenocarcinoma (black arrows).</p
