differentiated vulvar intraepithelial neoplasia

Definition: The term vulvar intraepithelial neoplasia (VIN) introduced in 1986 incorporates 3 grades of usual VIN (u-VIN I-III) and the differentiated VIN (d-VIN).

Although u-VIN is etiologically associated with the human papillomavirus (HPVs) infection, d-VIN represents an alternative HPV negative pathway of vulvar carcinogenesis.

In 2004, the u-VIN I category was abandoned and u-VIN II and III were merged. Further, an alternative Bethesda-like terminology scheme presenting the term vulvar intraepithelial lesion was proposed recently.

On the basis of histologic features, vulvar intraepithelial neoplasia (VIN) has been subdivided into the usual (u-VIN) and differentiated (d-VIN) types.

u-VIN is associated with HPV and occurs preferentially in young women at reproductive age. It has been further assorted into warty, basaloid, and mixed subtypes and subclassified into 3 grades (u-VIN I, II, and III).

d-VIN affects mainly postmenopausal women and behaves as a carcinoma in situ with a considerable risk of progression into invasive, mostly well differentiated and keratinizing HPV negative SCC.

References

 Skapa P, Zamecnik J, Hamsikova E, Salakova M, Smahelova J, Jandova K, Robova H, Rob L, Tachezy R. Human papillomavirus (HPV) profiles of vulvar lesions: possible implications for the classification of vulvar squamous cell carcinoma precursors and for the efficacy of prophylactic HPV vaccination. Am J Surg Pathol. 2007 Dec;31(12):1834-43. PMID: 18043037