A case of human papillomavirus infection and vulvar cancer in a young patient - "hit and run" theory.

Vulvar cancer (VC) is a rare disease, of which the squamous vulvar carcinomas (SVCs) are the most common histological subtype. SVC is often associated with human papillomavirus (HPV) infection. HPV- positive SVCs are multifocal, typically have non-keratinizing morphology, presence of koilocytes and tend to arise in younger women (<50 years), which are often smokers. The "hit and run" theory has been a subject of longstanding curiosity in tumor virology. The "hit and run" scenario suggests that viruses have an activating role in the cancer development and the viral genome may disappear after the host cell accumulates numerous mutations. Herein, a case of HPV- positive SVC in a 22-year-old patient with a possible "hit and run" scenario, is presented. Gynecological examination revealed a vulvar mass (3 cm) with ulcerated surface, located at the left Bartholini gland area. Punch biopsies of the lesion were performed. The histopathological examination revealed non-keratinizing squamous cell carcinoma (Grade 2) of the vulva and presence of koilocytes. P16 immunostaining was block-positive. HPV-testing of the specimen was negative. In the majority of cases, VC arising in young patients is associated with HPV. VC located in the BG area should be distinguished from BG carcinoma. Future studies should reconsider the third diagnostic (histological areas of apparent transition from normal elements to malignant ones) criteria for defining BG carcinoma. The "hit and run" theory is rarely mentioned in oncology, but should be considered in cancer- associated viruses. The "hit and run" affair suggests that viruses may cause more cancers than previously thought.