: Continues to be categorized separately from traditional SCC. 3. New Sections & Provisional Entities
: A dedicated new section covers epithelial tumours derived specifically from the nail bed. WHO Classification of Skin Tumours
: Entities are now generally listed in order from benign to malignant within each section to better reflect their neoplastic progression and clinical aggressiveness. : Continues to be categorized separately from traditional
: The term "variant" is now reserved strictly for genetic alterations in DNA sequences, rather than being used to describe morphological subtypes. WHO Classification of Skin Tumours
The (5th Edition, 2025) is the authoritative global standard for diagnosing and categorizing cutaneous neoplasms. Also known as the "Blue Books," this edition shifts toward a more integrated, multidisciplinary approach that combines traditional histopathology with advanced molecular genetics and immunohistochemistry. Key Structural & Conceptual Changes