Pathology Grand Rounds - Rethinking CK7 & CK20: From Reflex Stain to Rational Pane

At the conclusion of this activity, learners should be able to: * Evaluate the modern utility of coordinate CK7/CK20 expressions in carcinoma of unknown primary * Identify the specific scenarios in which CK7 and CK20 retain high diagnostic value * Apply a rational and tiered algorithm to determine tumor site of origin * Select appropriate IHC panels for the diagnosis of primary bladder, prostate, and kidney tumors * Discuss the role of molecular panels and AI-based approaches in resolving tumor origin