Fig. 6: p53 immunohistochemical patterns in p16-positive in situ (HSIL/uVIN) and vulvar squamous cell carcinomas (VSCC) of the vulva.

a Case 75, TP53 wild-type HSIL/uVIN showing complete absence of p53 staining in the basal layer juxtaposed with strong p53 in the parabasal layers (mid-epithelial pattern). b In situ hybridization in Case 75 shows that the cells exhibiting absence of p53 staining correspond to those cells with HPV RNA. c Case 74, TP53 wild-type HSIL/uVIN had absence of staining in the basal layer as well as parabasal layers (again mid-epithelial pattern). d Case 77, TP53 wild-type HSIL/uVIN had clusters of cells showing complete absence of p53 juxtaposed to clusters of cells showing strong p53 staining. Staining of the basal layer is absent. e Case 76, TP53 wild-type VSCC exhibited little p53 expression and f was diffusely positive for HPV-ISH.