MIB1 expression in basal cell layer: a diagnostic tool to identify premalignancies of the vulva

Sec62/Ki67 and p16/Ki67 dual-staining immunocytochemistry in vulvar cytology for the identification of vulvar intraepithelial neoplasia and vulvar cancer: a pilot study

PURPOSE

The aim of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual-staining protocol for the simultaneous expression of SEC62 and Ki67 in vulvar liquid-based cytology specimens for the identification of vulvar intraepithelial neoplasia (VIN) and vulvar cancer. In addition, we investigated the p16/Ki67 dual stain, which has already been established in cervical cytology.

MATERIALS AND METHODS

For this pilot study, residual material from liquid-based cytology was collected retrospectively from 45 women. The presence of one or more double-immunoreactive cells was considered as a positive test result for Sec62/Ki67 and p16/Ki67 dual staining. The test results were correlated with the course of histology.

RESULTS

All cases of VIN and vulvar cancer were Sec62/Ki67 and p16/Ki67 dual-stain positive, and normal and low-grade squamous intraepithelial lesions were all negative. The sensitivity of cytology for VIN + cases was 100% (22/22), whereas punch biopsy classified one case of vulvar carcinoma as inflammation. All cases with high-intensity (grades 3 and 4) Sec62 staining in Sec62/Ki67-positive cases were carcinomas.

CONCLUSIONS

The results of this study demonstrate that Sec62/Ki67 and p16 Ki67 dual-staining cytology could be a promising adjunctive diagnostic tool for VIN and squamous cell carcinoma, in addition to standard histology.

Phosphorylated S6 as an immunohistochemical biomarker of vulvar intraepithelial neoplasia

As life expectancy lengthens, cases of non-viral-associated vulvar squamous cell carcinoma and its precursor lesion, so-called differentiated vulvar intraepithelial neoplasia (VIN), continue to increase in frequency. Differentiated VIN often is difficult to recognize and failure to detect it before invasion results in morbidity and mortality. Thus, identification of a reliable biomarker for this type of lesion would be of great clinical benefit. Our recent studies have identified activation (ser235/236 phosphorylation) of ribosomal protein S6 (p-S6) in basal epithelial cells as an event that precedes and accompanies laminin γ(2) overexpression in most preinvasive oral dysplasias. To test this as a potential biomarker of vulvar dysplasia, we immunostained seven differentiated VINs and nine papillomavirus-related 'classic' VINs, most of which were associated with carcinoma, for p-S6. All carcinomas, all differentiated VINs, and most classic VINs contained regions of p-S6 staining in the basal layer, whereas basal and parabasal cells of normal vulvar epithelium and hyperplastic and inflamed lesions lacking cellular atypia were p-S6 negative. Laminin γ(2) was expressed in a subset of VINs, always occurring within basal p-S6 positive regions, as we had found previously for oral dysplasias. Lichen sclerosus is considered a potential precursor of vulvar carcinoma. Two lichen sclerosus lesions of patients with a concurrent carcinoma and one of six lichen sclerosus lesions without atypia or known concurrent carcinoma were basal p-S6 positive. In summary, there is a distinct difference in p-S6 basal cell layer staining between benign and neoplastic vulvar squamous epithelium, with consistent staining of differentiated VIN and of some lichen sclerosus lesions. These results support further studies to assess the potential of p-S6 as a biomarker to identify vulvar lesions at risk of progressing to invasive cancer.

Interobserver variability and the effect of education in the histopathological diagnosis of differentiated vulvar intraepithelial neoplasia

No published data concerning intraobserver and interobserver variability in the histopathological diagnosis of differentiated vulvar intraepithelial neoplasia (DVIN) are available, although it is widely accepted to be a subtle and difficult histopathological diagnosis. In this study, the reproducibility of the histopathological diagnosis of DVIN is evaluated. Furthermore, we investigated the possible improvement of the reproducibility after providing guidelines with histological characteristics and tried to identify histological characteristics that are most important in the recognition of DVIN. A total number of 34 hematoxylin and eosin-stained slides were included in this study and were analyzed by six pathologists each with a different level of education. Slides were reviewed before and after studying a guideline with histological characteristics of DVIN. Kappa statistics were used to compare the interobserver variability. Pathologists with a substantial agreement were asked to rank items by usefulness in the recognition of DVIN. The interobserver agreement during the first session varied between 0.08 and 0.54, which slightly increased during the second session toward an agreement between -0.01 and 0.75. Pathologists specialized in gynecopathology reached a substantial agreement (kappa 0.75). The top five of criteria indicated to be the most useful in the diagnosis of DVIN included: atypical mitosis in the basal layer, basal cellular atypia, dyskeratosis, prominent nucleoli and elongation and anastomosis of rete ridges. In conclusion, the histopathological diagnosis of DVIN is difficult, which is expressed by low interobserver agreement. Only in experienced pathologists with training in gynecopathology, kappa values reached a substantial agreement after providing strict guidelines. Therefore, it should be considered that specimens with an unclear diagnosis and/or clinical suspicion for DVIN should be revised by a pathologist specialized in gynecopathology. When adhering to suggested criteria the diagnosis of DVIN can be made easier.

Screening and follow up of vulval skin disorders

Vulval squamous cell carcinoma is relatively rare; however, up to 20% of women have significant vulval symptoms during their lifetime. Formal screening programmes for vulval disease have not been established. The evidence for the use of vulval cytology and vulvoscopy is reviewed. No randomised-controlled trials have compared follow-up regimens, and although a few consensus documents have been published, formal guidelines are lacking in Grade A evidence. With increasing pressure on healthcare resources, the possibility of identifying high-risk groups to optimise the use of follow up in specialist clinics is explored. Vulval disease is uncommon and there is no evidence that screening would decrease incidence. If high-risk groups can be identified, follow up should take place in specialised vulval clinics with experienced clinicians who are trained in vulval disease. Women with uncomplicated vulval conditions should be discharged to patient-initiated follow up or primary care. Central to the reduction of mortality and morbidity is increased awareness of vulval conditions among women and improved education of healthcare professionals, with particular understanding of the importance of physical examination.

Changes in the expression of oestrogen receptors and E-cadherin as molecular markers of progression from normal epithelium to invasive cancer in elderly patients with vulvar squamous cell carcinoma

AIMS

The most common vulvar squamous cell carcinoma (conventional SCC) occurs in elderly women and develops following a human papillomavirus (HPV)-negative pathway. Because the highest incidence of conventional SCC is observed in patients with low oestrogen levels (postmenopausal women), the aim was to investigate whether hormonal factors could play a role in the development of cancer.

METHODS AND RESULTS

The expression profile of oestrogen receptor α (ERα), ERβ and progesterone receptor (PR) in a section containing both normal and tumour tissue, as well as the SCC-associated vulvar lesion, was evaluated in 34 elderly patients. Also, as recent studies have identified E-cadherin as a novel transcriptional target of oestrogen signalling, the modulation of this epithelial-mesenchymal transition (EMT) marker was studied. Finally, the expression of the proliferation marker Ki67 and of the apoptotic marker p53 was assessed. Results showed that changes in both ERα and ERβ expression characterize the transition from normal epithelium to cancer in patients with vulvar SCC: ERα was lost in cancer while ERβ decreased, mainly showing cytoplasmic localization. A reduction in the expression of E-cadherin was also observed in tumours, compared to normal epithelium.

CONCLUSIONS

The data put the ER signalling pathway into the spotlight as a potentially important factor in vulvar carcinogenesis.

High levels of p53 expression correlate with DNA aneuploidy in (pre)malignancies of the vulva

The molecular pathogenesis of human papilloma virus-unrelated vulvar squamous cell carcinoma is not well known. Whether malignant progression of lichen sclerosus and differentiated vulvar intraepithelial neoplasia to vulvar squamous cell carcinoma could be accompanied by altered DNA content has not been studied extensively. DNA content in isolated nuclei of microdissected normal vulvar epithelium (n = 2), lichen sclerosus (n = 9), differentiated vulvar intraepithelial neoplasia (n = 13), and squamous cell carcinoma (n = 17) from 22 patients was measured via DNA image cytometry. For additional analysis, 6 differentiated vulvar intraepithelial neoplasia lesions were selected, bringing the number of patients to 28. p53 expression was determined by immunohistochemistry on consecutive tissue sections. Thirty-eight percent (5/13) of differentiated vulvar intraepithelial neoplasia lesions and 65% (11/17) of squamous cell carcinomas were DNA aneuploid or tetraploid. In lesions that contained differentiated vulvar intraepithelial neoplasia and adjacent squamous cell carcinoma, the ploidy status of differentiated vulvar intraepithelial neoplasia did not exceed that of squamous cell carcinoma. We observed a strong correlation between high p53 expression and DNA aneuploidy. This relation was also present at the level of a single nucleus, measured by sequential image cytometry of p53 immunohistochemistry followed by DNA image cytometry on formalin-fixed tissue sections. Similarly, we found p53-positive nonproliferating cells with increased DNA content in the superficial compartment of 6 additional solitary differentiated vulvar intraepithelial neoplasia lesions that were not associated with squamous cell carcinoma, indicating ascending aneuploid cells from the basal compartment. DNA ploidy measurements suggest that differentiated vulvar intraepithelial neoplasia has a higher malignant potential than lichen sclerosus and thus is a more likely precursor of squamous cell carcinoma. Furthermore, high p53 expression correlates with increased DNA content and aneuploidy; but it requires further research to unveil a possible causal relation.

Hypermutation in mantle cell lymphoma does not indicate a clinical or biological subentity

Mantle cell lymphoma is a prime example of a well-defined entity based on morphology, phenotype, genetics and also clinical features. Although most patients have an adverse clinical course, some have a better survival than others. The most consistently reported adverse prognostic parameter is a high mitotic rate. Recently, it has been shown that hypermutation in the immunoglobulin heavy-chain gene occurs in a subset of mantle cell lymphomas. It is, however, unclear whether the mutational status is stable over time within a given case, whether hypermutation might be influenced by therapy and how it is related to other relevant biological features of mantle cell lymphoma. In this study, we analyzed 23 typical mantle cell lymphoma cases with respect to mutational status and compared the results with clinicopathological and genetic data to determine whether the presence of mutation indicates a subentity with clinical or pathological relevance. We found somatic hypermutation in 26% of our cases and, interestingly, one case showed ongoing somatic hypermutation. In tumor cells of both mutated and unmutated cases, we found a preferential usage of V(H)3-21 (23%) and V(H)4-34 (19%). No significant correlations were found between mutation status and the other morphological and genetic features analyzed. In conclusion, our results provide additional evidence that mutation status in mantle cell lymphoma is better interpreted as a feature within the spectrum of disease that seems to have little clinical or pathological relevance.