J Clin Pathol 2006 May 19; (Read article online)

van Seters M, Ten Kate FJ, van Beurden M, Verheijen RH, Meijer CJ, Burger MP, Helmerhorst TJ

BACKGROUND: Differentiated vulvar intraepithelial neoplasia (VIN) is considered the presumable precursor of invasive squamous cell carcinoma (SCC) of the vulva. It is commonly assumed that differentiated VIN is related to lichen sclerosus (LS). However, argumentation for this is limited to a small number of studies describing epithelial alterations adjacent to vulvar SCC. AIM: To study the histology and human papillomavirus (HPV) status in patients with a history of both LS and VIN without coexistent SCC. METHODS: Original biopsies and surgical specimens of patients retrieved from the pathology files were revised for the presence of LS, VIN and (early) invasive SCC, specifically focused on the two different types of VIN: differentiated and undifferentiated. Thereafter, VIN-lesions were tested for the presence of HPV DNA. RESULTS: Twenty-seven patients fulfilled the criteria for LS and VIN without SCC. In all 27 patients we found LS related to undifferentiated VIN. Grading resulted in VIN 1 (n=10), VIN 2 (n=11) and VIN 3 (n=6). Additionally, VIN lesions from 26 patients could be tested for the presence of HPV DNA. In eight of them (31%) HPV DNA was present, predominantly type 16. Seven of these eight patients had VIN 2 or 3. During follow-up three patients progressed to (early) invasive carcinoma. In two of these patients, differentiated VIN was observed overlying early invasive SCC. CONCLUSIONS: VIN related to LS without coexisting SCC is likely to be undifferentiated, unlike what was previously thought. HPV DNA was demonstrated in 31% and strongly related to high-grade VIN.