Vulvar Intraepithelial Neoplasia: Historical Aspects and Current Status

Abstract

Vulvar intraepithelial neoplasia (VIN) is the currently accepted generic designation for the spectrum of vulvar lesions with the histologic features of squamous dysplasia and squamous cell carcinoma in situ. Although several classifications of VIN have been espoused in the past 20 years, VIN can be readily classified into two principal clinicopathologic types: classic (bowenoid) VIN and simplex (differentiated) VIN. This manuscript summarizes the historical development and current status of our knowledge about VIN. Information on the clinical and pathologic aspects are detailed and illustrated, as are considerations of differential diagnosis.

MIB1 expression in basal cell layer: a diagnostic tool to identify premalignancies of the vulva

“…This type of tumour is probably not associated with human papillomavirus (HPV) infection. [1][2][3][4] The less common type, accounting for about one-third of all vulvar squamous-cell carcinomas, is associated with HPV, predominantly HPV types 16 and 18. This type of tumour often occurs as a multifocal lesion in relatively young women and is usually preceded by high-grade usual VIN lesions (also referred to as classic VIN lesions).…”

“…This type of tumour often occurs as a multifocal lesion in relatively young women and is usually preceded by high-grade usual VIN lesions (also referred to as classic VIN lesions). 3,5,6 Recently, the International Society for the Study of Vulvovaginal Disease (ISSVD) has proposed a new nomenclature for premalignant vulvar lesions (see Table 1). 7 In usual VIN, the epithelium is thickened and accompanied by hyperkeratosis and/or parakeratosis.…”

“…There is little or no atypia above the basal or parabasal layers and it has a high degree of cellular differentiation, which combined with an absence of widespread architectural disarray hinders recognition. 2,3,9 Differentiated VIN is relatively infrequently diagnosed in its pure form and is often seen adjacent to lichen sclerosus and/or rapidly growing invasive vulvar squamouscell carcinoma. 3,8,10 Besides the difficulties in clinical and histological recognition of differentiated VIN, it is suggested that this form of VIN is highly proliferative and might be more likely to progress to an invasive neoplasm than lichen sclerosus and HPV-related VIN lesions.…”

“…2,3,9 Differentiated VIN is relatively infrequently diagnosed in its pure form and is often seen adjacent to lichen sclerosus and/or rapidly growing invasive vulvar squamouscell carcinoma. 3,8,10 Besides the difficulties in clinical and histological recognition of differentiated VIN, it is suggested that this form of VIN is highly proliferative and might be more likely to progress to an invasive neoplasm than lichen sclerosus and HPV-related VIN lesions. 2,3,11 Currently, no biomarker or diagnostic tool to predict possible invasive behaviour of premalignant vulvar lesions is available.…”

“…3,8,10 Besides the difficulties in clinical and histological recognition of differentiated VIN, it is suggested that this form of VIN is highly proliferative and might be more likely to progress to an invasive neoplasm than lichen sclerosus and HPV-related VIN lesions. 2,3,11 Currently, no biomarker or diagnostic tool to predict possible invasive behaviour of premalignant vulvar lesions is available. Because of the risk of malignant progression it is current practice that all patients with vulvar premalignancies undergo regular checkups.…”