Penile and Vulvar Intraepithelial Neoplasia



Penile and Vulvar Intraepithelial Neoplasia


Elsa F. Velazquez, MD





Key Facts


Terminology



  • Most warty, basaloid, and mixed VIN and PeIN replace 2/3 to entire thickness of epithelium (VIN III and PeIN III) and represent carcinoma in situ



    • VIN/PeIN I-II is rare


  • Differentiated VIN/PeIN is considered high-grade lesion


Microscopic Pathology



  • Differentiated (simplex) PeIN and VIN (HPV-unrelated)



    • Elongated and anastomosing rete ridges


    • Atypical basal cells with hyperchromatic nuclei


    • Subtle abnormal maturation (large eosinophilic keratinocytes)


    • Whorling and keratin pearl formation


    • Usually associated with LS&A


    • Preferential association with HPV-unrelated variants of invasive SCC (keratinizing SCC, verrucous carcinoma)


  • Basaloid, warty, and mixed (warty-basaloid) PeIN and VIN (a.k.a. usual VIN) (HPV-related)



    • Basaloid VIN/PeIN: Basaloid cells replace most to full thickness of epithelium


    • Warty VIN/PeIN: Pleomorphic cells with koilocytic changes replace most to full thickness of epithelium


    • Warty-basaloid VIN/PeIN: Pleomorphic cells with koilocytic changes seen on upper epithelium and basaloid cells replace lower epithelium


    • Warty, basaloid, and mixed VIN/PeIN is usually seen adjacent to HPV-related variants of invasive SCC (basaloid and warty types)







Vulvar intraepithelial neoplasia may appear as a raised, thickened white plaque image. This lesion is associated with an invasive component image that is exophytic. (Courtesy T. Quinn, MD.)






Enlarged keratinocytes with abundant eosinophilic cytoplasm throughout most of the epithelium are seen in differentiated PeIN/VIN. Characteristic keratin pearl formation is present image.


TERMINOLOGY


Abbreviations



  • Penile intraepithelial neoplasia (PeIN)


  • Vulvar intraepithelial neoplasia (VIN)


Synonyms



  • Erythroplasia of Queyrat, Bowen disease, squamous cell carcinoma in situ (SCCis)


Definitions



  • VIN and PeIN are considered intraepithelial (in situ) precursor lesions of invasive SCC


ETIOLOGY/PATHOGENESIS


Pathogenesis



  • Bimodal pathway of tumor progression in vulvar and penile SCC (HPV-related and HPV-unrelated)



    • Basaloid, warty, and warty-basaloid (mixed) VIN and PeIN are HPV-related (especially HPV 16)


    • Differentiated (simplex) VIN and PeIN are HPV-unrelated



      • May be related to lichen sclerosus et atrophicus (LS&A)


      • May be associated with P53 mutations


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Real incidence is unknown


    • 2/3 associated with invasive SCC


  • Age



    • 5th and 6th decades



      • About 1/2 of patients with VIN are < 40 years old


Presentation



  • Differentiated PeIN and VIN



    • Older patients


    • Usually arises in setting of chronic scarring, inflammatory dermatosis, especially lichen sclerosus et atrophicus (LS&A)


  • Warty, basaloid, and mixed PeIN and VIN (a.k.a. VIN of usual type in vulvar pathology)



    • Younger patients


    • Patients may have history of condyloma


Treatment



  • Surgery, locally destructive treatments


Prognosis



  • Most studies are retrospective and real prognosis remains unknown


MACROSCOPIC FEATURES


General Features



  • VIN and PeIN have heterogeneous gross appearance


  • Solitary or multifocal


  • Flat to slightly elevated hyperkeratotic or even condylomatous lesions


  • Pearly white, moist, erythematous, dark brown/black macules, papules, or plaques

Tags:
Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Penile and Vulvar Intraepithelial Neoplasia

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