[Immunohistochemistry of p16 and p53 in vulvar cancer]

Squamous cell carcinoma of the vulva may develop in association or independently of HPV infection. The relationship between pathogenesis, classification, immunohistochemical profile and prognosis has been studied in the literature with some discrepancies. The aim of this study was to observe the classical association of keratinizing carcinomas with the absence of HPV infection and warty and basaloid carcinomas with the presence of this virus. Therefore, we reviewed the clinic, morphology, and immunophenotype of 39 cases. The tumors were histologically classified into classic keratinizing squamous carcinoma (30), warty (5) and basaloid (4). In the statistical analysis, diffuse expression with p16 was significantly associated with younger age (p = 0.0025), presence of high-grade intraepithelial lesion (p < 0.0001), koilocytosis (p = 0.02), and morphological subtype (p = 0.02), and was inversely associated with the expression of p53 (p < 0.0001) and the presence of lichen sclerosus (p = 0.0051). It is curious that 4 keratinizing carcinomas of the cases studied presented coexpression of p16 and p53. Only one warty tumor was negative for p16 and positive for p53, and 9 keratinizing tumors were positive for p16 and negative for p53. Although these findings show that the use of hematoxylin and eosin could correctly define tumors associated with HPV, we strongly suggest the performance of immunohistochemistry, especially in squamous keratinizing classic carcinomas in young patients with a history of HPV.