Vulva
Premalignant lesions
Usual type vulvar intraepithelial neoplasia (uVIN)

Author: Sarah Strickland, M.D. (see Authors page)

Revised: 11 August 2016, last major update August 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Usual type vulvar intraepithelial neoplasia
Essential Features
  • Squamous cell carcinoma precursor lesion of the vulva
  • Distinct oncogenic pathway compared to differentiated type vulvar intraepithelial neoplasia (dVIN)
Terminology
  • The 2015 International Society for the Study of Vulvovaginal Disease (ISSVD) classifies vulvar squamous intraepithelial lesions as follows:

  • The 2014 World Health Organization Classification of Tumors of the Vulva classification is as follows:
    • Low grade squamous intraepithelial lesion (LSIL)
    • High grade squamous intraepithelial lesion (HSIL)
    • Differentiated type VIN
  • Epidemiology
    • Younger women (30-50 years)
    • Risk factors include HPV infection, smoking, immunosuppression, history of genital herpes and increased number of sexual partners
    • Rate has increased over the last three decades while rate of vulvar squamous cell carcinoma has stayed relatively stable (J Reprod Med 2000;45:613, Obstet Gynecol 2006;107:1018)
    Sites
    • Labia majora, labia minor and posterior fourchette are most frequent sites
    • May also affect clitoris, mons pubis, perineal and perianal areas
    Etiology
    • Human papillomavirus (HPV) driven process (high risk subtypes HPV 16 and 18 are most common)
    Clinical Features
    Diagnosis
    • Vulvar biopsy: optimally a punch or small incisional biopsy taken from the edge of the lesion including a small piece of normal tissue (Crit Rev Oncol Hematol 2008;68:131)
    Prognostic Factors
    Treatment
    • Local excision, imiquimod, cidofovir, photodynamic therapy or laser ablation
    Clinical Images

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    Various images

    Micro Description
    • Hyperkeratosis and parakeratosis
    • Acanthosis with club shaped rete ridges
    • Disorientation of the cells above the basal cell layer with variable extension to the surface
    • Nuclear clumping with mitotic figures
    • Intact basement membrane
    • Variable extension into skin appendages
    Micro Images

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    Vulvar Intraepithelial Neoplasia III


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    VIN III H&E stains


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    Vulvar epithelium

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    uVIN 3 basaloid type

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    Solitary usual VIN lesion

    Virtual Slides

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    Vulvar intraepithelial neoplasia, usual type,
    with low grade dysplasia (VIN 1)

    Positive Stains
    • p16: diffuse, strong, cytoplasmic and nuclear band-like pattern
    • Ki67: extends into upper two thirds of the epithelium
    Negative Stains