[1207] Vulvar Squamous Cell Carcinoma: A Study of 71 Tumors with Emphasis on Characterization and Distinction of Tumors Associated with HPV-/Classic VIN from Non-HPV-/Differentiated VIN-Associated Tumors

Rajmohan Murali, Matthew Cesari, Kay Park. Memorial Sloan-Kettering Cancer Center, New York, NY; Sunnybrook Health Sciences Centre, Toronto, ON, Canada

Background: Vulvar squamous cell carcinoma (SCC) develops via human papillomavirus (HPV)-associated and non-HPV-associated pathways. The more common, non-HPV-associated keratinizing SCC typically occurs in older women and arises in a background of differentiated vulvar intraepithelial nesoplasia (dVIN) and lichen sclerosus (LS). The HPV-associated warty/basaloid form of SCC occurs in younger women and arises in a background of classic VIN (cVIN). In this study, we investigated the morphologic spectrum of vulvar SCC and its associated lesions with respect to pathogenesis.
Design: Patients diagnosed with invasive vulvar SCC between 1978 and 1998 were identified from the MSKCC institutional pathology database. Histopathologic features were reviewed, and their associations with HPV changes and VIN type were analyzed.
Results: Seventy-one patients with invasive vulvar SCC were identified. The median tumor size and depth were 13mm and 3.0mm, respectively. The tumor grade was 1, 2 and 3 in 22 (31%), 27 (38%) and 22 (31%) cases, respectively. Variable amounts of keratin were present in 62 tumors, 50 of which contained keratin pearls. HPV-related change and associated lichen sclerosus were present in 29 (41%) and 25 (35%) cases, respectively, with both being present in 7 tumors. Associated VIN was present in 67/70 (96%) tumors, and was of differentiated, classic, mixed, or indeterminate types in 38 (54%), 19 (27%), 4 (6%), and 6 (9%) tumors, respectively. Several features were significantly associated with HPV changes and VIN type:

Table 1. Significant associations with HPV changes
 HPV-associated tumorsNon-HPV-associated tumorsp-value
Median size7mm18mm0.005
Median depth of invasion1.7mm6.3mm<0.0001
Histologic grade 152%17%0.007
Perineural invasion7%45%0.0005
Pushing borders38%2%0.0002

Table 2. Significant associations with VIN type
 dVIN-associated tumorscVIN-associated tumorsp-value
Median size18mm5.5mm0.02
Median depth of invasion5mm1.4mm0.0007
Moderate-marked keratin74%37%0.005
Keratin pearls84%42%0.002
Perineural invasion39%11%0.03
Infiltrating borders97%61%0.001
Associated HPV changes15%95%<0.0001
Associated lichen sclerosus55%5%0.0002

Conclusions: Vulvar SCCs associated with HPV/cVIN changes have distinct pathologic features that distinguish them from those associated with dVIN and lacking HPV changes. Confirmatory HPV testing by immunohistochemistry and molecular detection would be of interest and is in progress.
Category: Gynecologic & Obstetrics

Tuesday, March 5, 2013 1:00 PM

Poster Session IV # 236, Tuesday Afternoon


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