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:
|HPV-associated tumors||Non-HPV-associated tumors||p-value|
|Median depth of invasion||1.7mm||6.3mm||<0.0001|
|Histologic grade 1||52%||17%||0.007|
|dVIN-associated tumors||cVIN-associated tumors||p-value|
|Median depth of invasion||5mm||1.4mm||0.0007|
|Associated HPV changes||15%||95%||<0.0001|
|Associated lichen sclerosus||55%||5%||0.0002|