High Grade Vulvar Squamous Intraepithelial Lesion

**Semantic type:** Neoplastic Process

**Definition:** An intraepithelial lesion of the vulvar squamous epithelium associated with HPV infection. It is characterized by loss of maturation, nuclear hyperchromasia, high nuclear:cytoplasmic ratios, cytological and architectural atypia, and mitoses. Two morphological patterns have been described: basaloid (undifferentiated) and warty (condylomatous, bowenoid). It carries a significant but relatively low risk of progression to squamous cell carcinoma if untreated. (WHO 2020)

**Synonyms:** - Grade 2 VIN - Grade 2 Vulvar Intraepithelial Neoplasia - Grade 3 VIN - Grade II VIN - Grade II Vulvar Intraepithelial Neoplasia - Intraepithelial Neoplasia of Vulva Grade 2 - Intraepithelial Neoplasia of the Vulva Grade 2 - VIN 2 - VIN 2 of Usual Type - VIN 3 - VIN 3 of Usual Type - VIN Grade 2 - VIN, Usual Type - Vulva Intraepithelial Neoplasia Grade 2 - Vulva Intraepithelial Neoplasia Grade 3 - Vulvar Bowen Disease - Vulvar Bowenoid Dysplasia - Vulvar HSIL - Vulvar High Grade Squamous Intraepithelial Lesion - Vulvar High-Grade Squamous Intraepithelial Lesion - Vulvar Intraepithelial Neoplasia 2 of Usual Type - Vulvar Intraepithelial Neoplasia 3 of Usual Type - Vulvar Intraepithelial Neoplasia Grade 2 - Vulvar Intraepithelial Neoplasia Grade 3 - Vulvar Intraepithelial Neoplasia, Usual Type - Vulvar Moderate Squamous Dysplasia - Vulvar Severe Squamous Dysplasia