Which of these is FALSE of vulvar carcinoma?

Most common histological type of ca vulva is squamous cell carcinoma In situ vulval cancer occurs more commonly in young females due to rising incidence of HPV infection. Basaloid or way types Keratinizing 40% of squamous 60 % of squamous Multifocal Unifocal Younger patients Older patients Related to HPV Not related to HPV, related to lichen sclerosis Usual VIN, immunosuppression, smoking related Differentiated VIN, chronic inflammatory dermatosis