Histopathology of vascular anomalies: Update based on the revised 2014 ISSVA classification

Precise diagnosis of childhood vascular anomalies is challenging, and requires careful correlation of clinical findings, diagnostic imaging, histopathology and genetic analysis. Skin and soft tissue biopsies remain an important element in the complete evaluation of many vascular anomalies included in the revised 2014 International Society for the Study of Vascular Anomalies (ISSVA) classification. Here we present an overview of the light microscopic and immunohistochemical features of the entities in this updated classification scheme, with emphasis on newly-included diagnoses such as PTEN hamartoma of soft tissue.