: Progress in identifying gene fusions (e.g., YAP1::MAML2 in poromas) has enhanced diagnostic accuracy for sweat gland and hair follicle tumours.
: Continues to be categorized separately from traditional SCC. 3. New Sections & Provisional Entities 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. : Progress in identifying gene fusions (e
: Significant updates were made to dendritic cell and histiocytic neoplasms, as well as T-cell and NK-cell disorders. WHO Classification of Skin Tumours
: Updates focus on high-risk subtypes. Sarcomatoid differentiation is now the primary acknowledged uncommon subtype of Squamous Cell Carcinoma (SCC).
: The term "variant" is now reserved strictly for genetic alterations in DNA sequences, rather than being used to describe morphological subtypes.