: Entities are now generally listed in order from benign to malignant within each section to better reflect their neoplastic progression and clinical aggressiveness.

: Significant updates were made to dendritic cell and histiocytic neoplasms, as well as T-cell and NK-cell disorders.

: The classification reaffirms the 9-pathway model for melanoma, which classifies lesions based on sun exposure (UV damage), anatomical site (e.g., acral, mucosal), and specific molecular drivers.

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