: Entities are now generally listed in order from benign to malignant within each section to better reflect their neoplastic progression and clinical aggressiveness.
: "Primary cutaneous NUT (Nuclear protein in testis) carcinoma" is included as a new provisional entity. 4. Adnexal & Soft Tissue Tumours
: Progress in identifying gene fusions (e.g., YAP1::MAML2 in poromas) has enhanced diagnostic accuracy for sweat gland and hair follicle tumours. 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).
: This term is now used for "intermediate" lesions that exhibit borderline biological behavior but have specific molecular signatures (e.g., BAP1 inactivation or WNT pathway alterations). : Entities are now generally listed in order
: A new chapter focusing on the adverse prognostic implications of systemic cancers metastasizing to the skin.
: A dedicated new section covers epithelial tumours derived specifically from the nail bed. Adnexal & Soft Tissue Tumours : Progress in
: Significant updates were made to dendritic cell and histiocytic neoplasms, as well as T-cell and NK-cell disorders.