This short video explains the microscopic morphological features that can be appreciated in prion diseases, especially in Creutzfeldt-Jakob Disease (CJD) and which specific marker can be used in immunohistochemical studies. Timeline: 0:00 - Creutzfeldt-Jakob Disease (CJD) gross features 0:21 - Microscopic features of CJD 1:33 - Absence of inflammatory infiltrate or not? 1:59 - Immunohistochemistry