Correlation of PD-1 and PD-L1 expression in oral leukoplakia and oral squamous cell carcinoma: an immunohistochemical study.

The programmed cell death protein (PD-1)/programmed cell death protein ligand (PD-L1) pathway and cytotoxic T lymphocyte antigen are the most important co-stimulatory molecules that play a key role in the negative regulation of T cells during carcinogenesis. We aimed to evaluate the immunohistochemical expression of PD-1 and PD-L1 in oral leukoplakia and squamous cell carcinoma compared with normal oral mucosa. Twenty-five cases of oral squamous cell carcinoma, oral leukoplakia and normal oral mucosa tissue specimens were immunohistochemically stained to assess PD-1 and PD-L1 expression. The PD-L1 positivity of subepithelial TAFs (p < 0.001) increased with increasing grades of oral leukoplakia. Pearson's correlation indicated a high positive correlation between the PD-L1 labelling index of epithelial tumour cells and the PD-1 labelling index of tumour infiltrating lymphocytes (p value: 0.005) in OSCC. A high positive correlation was noted between the H-score of PD-L1 positive tumour epithelial cells and the H-score of PD-1 positive tumour infiltrating lymphocytes in OSCC (p value: 0.001). PD-L1 positivity increased in dysplastic epithelial cells from premalignant lesions to malignancy. The sub-epithelial PD-L1 positive TAFs were higher in oral leukoplakia compared to OSCC inferring that PD-L1 positivity in TAFs decreased with malignant transformation. The PD-1 positivity in TILs was higher in oral leukoplakia than in OSCC.

Expression of transmembrane protein aquaporin-3 in oral epithelial dysplasia and oral squamous cell carcinoma.

OBJECTIVES: The objective of this study was to evaluate aquaporin-3 (AQP3) expression in patient samples of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), thereby assessing the potential of AQP3 as a molecular marker for tumor progression. STUDY DESIGN: An in vitro comparative study was done to determine the AQP3 expression on 20 surgical biopsy specimens each of OED and OSCC using immunohistochemistry. Twenty specimens of normal oral mucosa were kept as controls. The results were statistically analyzed using one-way analysis of variance and post hoc analysis. RESULTS: The expression of AQP3 was analyzed and further semiquantified using H-scores. The mean H-score showed a statistically significant difference between OSCC, OED, and normal oral mucosa (P < .05). There was a significant increase in the expression of AQP3 in OSCC and OED compared to normal oral mucosa. The highest expression was observed in OSCC (P < .01). CONCLUSION: The observations of the study indicate that staining intensity of AQP3 increased from dysplastic noninvasive lesion to invasive OSCC, suggesting a possible role of AQP3 as a biomarker for tumor progression.

Prevalence of oral potentially malignant disorders and oral malignant lesions: A population-based study in a municipal town of southern Kerala.

Oral cancer burden poses a major challenge in India. Oral cancer in the majority of instances arises from preexisting oral potentially malignant disorders (OPMDs). Early detection of OPMD and elimination of primary risk factors such as smokeless and smoking tobacco help in reduction of oral cancer. A study was conducted to find the prevalence and associated risk factors of OPMDs and oral malignant lesions (OMLs) in Punalur township of South Kerala. A total of 2368 patients were screened, out of which 156 were identified with OPMD and 5 with OML. A male predominance was noted for both OPMD and OML. Strong association with smokeless tobacco and smoking tobacco habits was seen with patients having OPMD and OML.

Ameloblastic fibro-odontoma.

INTRODUCTION: Ameloblastic fibro-odontoma (AFO) is a quite rare, mixed odontogenic tumour generally seen in the early stages of life. Frequent signs of this tumour are asymptomatic swelling, delayed tooth eruption and mixed radiological appearance within well-defined borders. Management of the lesion includes enucleation of the tumour and long-term follow-up. PRESENTATION OF CASE: A 10-year-old girl was referred to our oral and maxillofacial surgery clinic with an incidental radiological finding of radiopaque mass in the posterior region of maxilla. OPG showed unerupted tooth bud of upper right second molar and was being prevented from eruption by the odontome. Under general anaesthesia, the lesion was enucleated and the permanent right upper second molar tooth bud removed. DISCUSSION: Mixed odontogenic tumours are a group of rare and interesting lesions which can mislead the clinician to variety of differential diagnosis. Adequate clinical and radiological investigations, proper surgical excison, accurate histopathological diagnosis, and long term follow up will ensure the right treatment plan for the patient. CONCLUSION: The possibility of a mixed rare tumour should be kept in mind by the clinician where they deal with the swellings of posterior maxilla in children. Histological assessment revealed a final diagnosis of ameloblastic fibro-odontoma.