WT1 and Wilms tumor: Solid pRCC will be positive for CK7 and AMACR, but negative for WT1 and CD57, while, conversely, metanephric adenoma is only positive for WT1 and CD57, whereas Wilms’ tumor expresses only nuclear immunoreactivity for WT1 and, rarely, isolated cells with CK7 cytoplasmic positivity.