Nucleolar organizer regions in human oral verrucous carcinoma and adjacent lining epithelium.

The epithelium adjacent to an oral squamous cell carcinoma is at risk of undergoing precancerous changes. Even after such changes occur, however, the adjacent epithelium remains histologically similar to normal mucosa. We investigated five argyrophilic nucleolar organizer region (AgNOR)-related features in samples of oral verrucous carcinoma (VeCa) and their corresponding adjacent lining epithelium (adj. VeCa). Morphometric characteristics of AgNORs in oral adj. VeCa and oral VeCa were compared to normal mucosa epithelium, squamous cell carcinoma and oral mucosa epithelium adjacent to squamous cell carcinoma findings that we published earlier. Although adj. VeCa and normal oral mucosa were histologically similar, total AgNOR volume differentiated adj. VeCa from normal oral mucosa, but revealed no significant difference between VeCa and adj. VeCa. Total AgNOR volume/nuclear volume discriminated VeCa from adj. VeCa and normal oral mucosa. Certain AgNOR parameters provide a complementary tool for discriminating VeCa from adj. VeCa and normal oral mucosa, and also for detecting incipient malignant changes in epithelium adjacent to VeCa. Use of the AgNOR technique is cost-effective, because it can be performed on paraffin sections.

High incidence of DNA ploidy abnormalities and increased Mcm2 expression may predict malignant change in oral proliferative verrucous leukoplakia.

AIMS: To assess the DNA content of cases of oral proliferative verrucous leukoplakia (PVL) and correlate the DNA ploidy findings with the expression of Mcm2, geminin, and Ki67, and with clinicopathological data. METHODS AND RESULTS: DNA quantification was performed by image cytometry using the ACIS III Automated Cellular Imaging System. Expression of Ki67, Mcm2 and geminin was determined by immunohistochemistry. There were 21 cases of PVL, the female/male ratio was 6:1, and the average age was 65.5 years. Seventeen patients (81.0%) did not report tobacco and alcohol consumption. Nine patients (42.9%) developed verrucous or squamous cell carcinoma. Levels of Mcm2 expression showed a positive correlation with increasingly severe epithelial changes (P = 0.03). Twenty patients had their DNA examined by ACIS III, and 19 (95%) showed aneuploidy. The frequency and severity of aneuploidy (P < 0.0001), the mean values of the DNA heterogeneity index (P < 0.0001) and the 5n-exceeding fractions (P = 0.0007) increased according to epithelial alterations. Abnormal DNA content was observed even in the more indolent lesions. CONCLUSIONS: Mcm2 expression and DNA ploidy analysis could be used to predict areas of malignant transformation. The clinicopathological findings associated with the immunohistochemical and DNA ploidy results support the distinct and aggressive profile of this entity.

Oral squamous cell carcinoma versus oral verrucous carcinoma: an approach to cellular proliferation and negative relation to human papillomavirus (HPV).

Human papillomavirus (HPV) has been cited as a possible initiating agent in the pathogenesis of oral cancer. However, the literature tends to be both controversial and inconclusive about the prevalence of HPV and its potential for proliferation in oral squamous cell carcinoma (SCC). The aim of this study was to investigate the cellular proliferation and the presence of HPV in SCC and verrucous carcinoma (VC). Forty-seven samples of SCC were selected and divided into three groups: 39 SCC, 8 VC, and 9 of normal mucosa (control-CT). Quantitative analyses of all groups showed a greater expression of PCNA, followed by Ki-67 and cyclin B1. A significant difference was observed in cyclin B1 expression in the SCC group compared with VC. PCNA, Ki-67, and cyclin B1 were statistically significant when comparing the SCC and CT groups. However, when SCC and VC were compared, there was no difference in Ki-67 expression. Our results showed that only cyclin B1 had an association with histological grade, and that poorly differentiated tumors presented a higher expression of cyclin B1. Therefore, considerable differences in the cellular proliferation between SCC and VC were observed, and no correlation with HPV was established, since all samples were negative for HPV.

Immunohistochemical evaluation of intermediate filament proteins in squamous papilloma and oral verrucous carcinoma.

OBJECTIVE: Cytokeratins (CKs) are the intermediate filament proteins of the epithelium cells, which have become important markers of normal and abnormal cell differentiation. The goal of the present study was to investigate the expression pattern of CK 10, 13, 14 and 16 in oral verrucous carcinoma (OVC) and oral squamous papilloma (OSP). MATERIAL AND METHODS: Formalin-fixed paraffin-embedded sections from eight cases of each lesion were assessed. Immunohistochemistry was carried out using streptoavidin-biotin complex method. RESULTS: In OVC, CK 10 was expressed in suprabasal to superficial layers whereas in OSP mainly in superficial layer. CK 13 was detected in prickle and superficial cells in most cases of OVC and in suprabasal to superficial cells of OSP. All the cell layers of OVC reacted positively for CK 14 while basal and suprabasal layers of OSP were more pronounced for CK 14. Finally, CK 16 was observed in suprabasal to superficial layer in OVC and the majority cases in OSP showed only superficial reactive cells. CONCLUSIONS: CK 10, 13, 14 and 16 immunohistochemical profile emphasis the biological behavior of the studied lesions and confirm the use of these proteins as markers of differentiation.

Detection and expression of Epstein-Barr Virus (EBV) DNA in tissues from penile tumors in Brazil.

Epstein-Barr Virus (EBV) is prevalent in all human populations and high titers of antibody correlate with specific malignancies such as Burkitt's lymphoma, nasopharyngeal carcinoma, and Hodgkin's disease. Our study detected EBV DNA in 20 of 21 penile tumor samples using PCR reaction. Expression of EBV protein LMP-1 was identified in tumor cells from two EBV PCR-positive tumors. Our findings indicate that EBV can be implicated in rising and/or progression of penile tumors independently of the histological type.