Expression of podoplanin in oral premalignant and malignant lesions and its potential as a biomarker.

Aim: To analyze and compare the expression of podoplanin in normal oral tissues, leukoplakia and oral squamous cell carcinoma (OSCC) and to predict its use as a biomarker. Materials and Methods: Ninety‑two formalin fixed paraffin embedded tissue samples comprising of 32 cases of leukoplakia, 50 cases of OSCCs and ten normal gingival samples. The samples were retrieved from archives and immunohistochemically analyzed using podoplanin. Appendix tissue samples were used for control purposes. The results were tabulated and statistically analyzed using ANOVA/Kruskal–Wallis test with post‑hoc tests, where demographic details are compared and analyzed using Pearson Chi‑square test. Results: The study results showed, absence of podoplanin expression in the epithelium of all the gingival samples (Group I). Positive podoplanin expression noticed in 19 out of 32 (59.4%) cases of leukoplakia (Group II) and 41 out of 50 (82%) cases of OSCCs (Group III). The expression of podoplanin among different groups was highly significant (P = 0.000). Conclusion: The podoplanin may be considered as a predictor marker in assessing malignant transformation of premalignancies and prognosis of oral malignancy. Indeed it is believed that podoplanin might play a role in tumor progression though exact mechanism is not fully elucidated. Further research is required to understand its exact pathophysiology.

Peripheral squamous odontogenic tumor.

A case of peripheral squamous odontogenic tumor is described in a 60-year-old female who presented with a sessile growth in the right posterior mandible. Radiographic examination revealed no evidence of a central lesion in bone. With the characteristic histopathological picture of benign-appearing islands of squamous epithelium scattered randomly against a background of mature fibrous connective tissue, the tumor was diagnosed as peripheral squamous odontogenic tumor (PSOT). The epithelial islands showed peripheral cuboidal or flattened cells, microcyst formation, individual cell keratinization, and keratin pearl formation.

Expression of heat shock protein70 in oral submucous fibrosis and oral squamous cell carcinoma: An immunohistochemical study.

Background: Heat shock proteins are a highly conserved group of protective cellular proteins whose synthesis is increased in response to a variety of environmental or pathophysiological stresses. Heat shock proteins are useful biomarkers for carcinogenesis in tissues and signal the degree of differentiation and the aggressiveness of cancers. Regulation of heat shock protein 70 (HSP70) expression in oral submucous fibrosis is not known much, and the aim of this study was to evaluate HSP70 expression in oral submucous fibrosis and oral squamous cell carcinoma by immunohistochemical method and to understand the role of HSP70 in tumorigenesis. Materials and Methods: Immunohistochemical method was used to detect HSP70 expression in normal oral mucosa, oral submucous fibrosis (n=30) and oral squamous cell carcinoma (n=20). HSP70 immunoreactivity was correlated with histological and clinicopathological features. Results: A significant increase in expression of HSP70 was observed (P<0.000) as the tissue progressed from oral submucous fibrosis towards oral squamous cell carcinoma. Conclusion: HSP70 is synthesized upon stress situations arising in cells of all living organisms. Expression of HSP70 indicates that stress plays an important role as a predisposing factor in oral submucous fibrosis and its subsequent progression to oral squamous cell carcinoma.

A comparative study on microwave and routine tissue processing.

Aim and Objective: The present study was aimed at assessing the rapid microwave-assisted tissue processing and staining to determine if it can replace standard formalin-fixed and paraffin-embedded processing and staining technique. Materials and Methods: The study group consisted of 15 oral mucosal biopsies. The specimens were fixed in 10% formalin for 24 hours to ensure adequate fixation and their gross features were recorded, photographed, and then the specimens were cut into equal halves to be processed by both conventional and microwave histoprocessing methods and then subsequently stained with H and E by microwave and conventional methods. The stained slides in each group processed by both microwave and routine methods were randomly numbered for a blind study and circulated among six observers. All the observers were asked to grade each parameter into Excellent/Good/Average/Poor in a data sheet comprising a total of six parameters. These gradings were given a numerical value of 4, 3, 2 and 1, respectively. The parameters included in the data sheet were cellular clarity, cytoplasmic details, nuclear details, color intensity, interface of epithelium and connective tissue. Wilcoxon-matched pairs signed rank test (non-parametric) was used to calculate the test of significance (P value). Results: The total processing time involved in microwave was 42 minutes and 270 minutes for the conventional method. H and E staining in microwave took 33 minutes and 40 minutes for conventional method. Conclusions: The individual scores by different observers regarding the various parameters included in the study were statistically insignificant, the overall quality of microwave-processed and microwave-stained slides appeared slightly better than conventionally processed and stained slides.

Argyrophilic nucleolar organizer regions in inflammatory, premalignant, and malignant oral lesions: a quantitative and qualitative assessment.

BACKGROUND AND OBJECTIVE: Argyrophilic nucleolar organizer regions (AgNORs) have found widespread application in the past, especially in tumor histopathology. This study was undertaken to evaluate the significance of various AgNOR parameters and to assess their role in differentiating hyperplastic, premalignant, and malignant lesions. MATERIALS AND METHODS: The study sample consisted of archival biopsy specimens of ten squamous cell carcinomas, ten premalignant lesions, and five inflammatory lesions. Two biopsies from normal mucosa acted as control. AgNORs were assessed both quantitatively and qualitatively. The data were analyzed using Student's independent t-test, one-way analysis of variance (ANOVA), and multiple range test (Tukey-HSD). RESULTS: Quantitatively significant difference existed in the number of AgNORs between the normal mucosa, inflammatory lesions, and carcinomas, but the premalignant lesions failed to differ significantly from the normal mucosa. The number of AgNORs was found to be related to epithelial proliferation. Qualitatively, in terms of size, shape, and pattern of distribution, the normal mucosa and inflammatory lesion were alike, but the premalignant and malignant lesions differed significantly from the normal, with a marked degree of AgNOR pleomorphism being observed in carcinomas. CONCLUSIONS: AgNOR quantity is strictly proportional to the proliferative activity of the cell and does not necessarily indicate malignancy. It is the qualitative characteristics of AgNOR that help to differentiate hyperplastic, premalignant, and malignant lesions.