Evaluation of immunohistochemical markers, CK17 and SOX2, as adjuncts to P53 for the diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN)

Histological diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN), the precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma (VSCC), can be challenging, as features of dVIN may mimic those of non-dysplastic dermatoses. To aid the diagnosis, p53-immunohistochemistry (IHC) is commonly used, and mutant expression patterns are used to support a histological diagnosis of dVIN. However, a proportion of dVIN can show wild-type p53-expression, which is characteristic of non-dysplastic dermatoses. Furthermore, recent research has identified a novel precursor of HPV-independent VSCC—the p53-wild-type differentiated exophytic vulvar intraepithelial lesion (de-VIL). Currently, there are no established diagnostic IHC-markers for p53-wild-type dVIN or de-VIL. We evaluated IHC-markers, cytokeratin 17 (CK17), and SRY-box 2 (SOX2), as diagnostic adjuncts for dVIN. For this, IHC-expression of CK17, SOX2, and p53 was studied in dVIN (n = 56), de-VIL (n = 8), and non-dysplastic vulvar tissues (n = 46). For CK17 and SOX2, the percentage of cells showing expression, and the intensity and distribution of expression were recorded. We also performed next generation targeted sequencing (NGTS) on a subset of dVIN (n = 8) and de-VIL (n = 8). With p53-IHC, 74% of dVIN showed mutant patterns and 26% showed wild-type expression. Median percentage of cells expressing CK17 or SOX2 was significantly higher in dVIN (p53-mutant or p53-wild-type) and de-VIL than in non-dysplastic tissues (p < 0.01). Diffuse, moderate-to-strong, full epithelial expression of CK17 or SOX2 was highly specific for dVIN and de-VIL. With NGTS, TP53 mutations were detected in both dVIN and de-VIL. We infer that immunohistochemical markers CK17 and SOX2, when used along with p53, may help support the histological diagnosis of dVIN

Relationship of human papillomavirus with seborrheic keratosis of the female genital tract - a case-series and literature review

Seborrheic keratoses (SKs) are benign lesions of uncertain etiology, which can develop in both genital and extra-genital locations. For genital SKs there has been conjecture about the pathogenic role of human papillomavirus (HPV), in view of the frequent association of this virus with genital lesions. In light of the potential consequences on patient management, we investigated the relationship between HPV and SKs of the female genital tract (FGT). For this, we evaluated the current evidence on this relationship by performing an in-depth review of the literature. Furthermore, to add to the evidence on this association, we investigated the presence of HPV in a series of vulvar SKs (n=15), using a novel multimodal approach. This involved whole tissue section-polymerase chain reaction (WTS-PCR) using SPF10-DEIA-LiPA25 for HPV detection and genotyping. In addition, immunohistochemistry (IHC) was performed with cellular biomarkers p16 and MIB-1, and viral biomarker E4, to augment HPV-testing. Finally, laser-capture microdissection-PCR (LCM-PCR) was performed to locate HPV to specific lesional cells, and to rule out incidental detection of resident HPV with WTS-PCR. Our findings from the literature review as well as the case-series are presented