Abstract: Vascular anomalies can be primarily categorized into two major groups: vascular tumors and vascular malformations. In 1982, Mulliken and Glowacki proposed a revolutionary biological classification. Specifically, based on the proliferation characteristics of endothelial cells, these anomalies were differentiated into "hemangiomas" and "vascular malformations". In 1996, this classification system was adopted by the International Society for the Study of Vascular Anomalies (ISSVA) as the standard classification, and has been undergoing continuous refinement up to the present. In May 2025, the latest ISSVA World Congress was convened in Paris. The 2018 classification system, which is currently in wide use, was further optimized. A substantial number of structural and detailed adjustments were made, rendering the new classification system more streamlined. Consequently, its usability has been remarkably enhanced. This evolution of the ISSVA classification mirrors the deepening of the understanding from the morphological level to the molecular mechanism level. Every update holds milestone significance for the standardization of the diagnosis and treatment of vascular diseases globally. This paper aimed to introduce and interpret the newly revised ISSVA classification (2025 version), providing a reference for clinical practice, scientific research, and academic exchanges.

Key words: Vascular anomalies, ISSVA, Hemangioma, Vascular malformations, Classification