Vulvar squamous intraepithelial lesion histology

2015 and 2004 International Society for the Study of Vulvar Disease (ISSVD) modified terminology for VIN: the term VIN applies only to histologically high-grade squamous lesions (former terms: VIN 2 and VIN 3 and differentiated VIN 3). In the 2015 classification, VIN 2,3 are combined into vulvar HSIL.