The absence of high-risk HPV combined with specific p53 and p16INK4a expression patterns points to the HPV-independent pathway as the causative agent for vulvar squamous cell carcinoma and its precursor simplex VIN in a young patient.

Simplex vulvar intraepithelial neoplasia (VIN) is an important precursor of vulvar invasive squamous cell carcinoma and characteristically occurs in postmenopausal women. In this report, the absence of high-risk human papillomavirus (HPV) combined with specific p53 and p16INK4a expression patterns points to the HPV-independent pathway as the causative agent for vulvar squamous cell carcinoma in a 28-year-old woman. Its precursor simplex VIN was initially interpreted as eczema. Although simplex VIN has a predilection for postmenopausal women, it can occur in young patients. The development of invasive vulvar squamous cell carcinoma underlines the importance of including simplex VIN in the differential diagnosis of vulvar lesions, even at a young age. Furthermore, knowledge about the HPV status in the tumor and thus the underlying causative pathway can alert the gynecologist for the presence or absence of multicentric lower genital tract disease, as this is frequent in the HPV-dependent and not in the HPV-independent pathway.