Oral submucous fibrosis: An enigmatic morpho-insight.

Oral submucous fibrosis (OSMF) is a chronic progressive, scarring disease affecting oral, oropharyngeal, and sometimes the esophageal mucosa. It is characterized by the progressive fibrosis of the submucosal tissue. The pathogenesis of OSMF has been directly related to the habit of chewing areca nut and its commercial preparation, which is widespread in Indian subcontinent and Southeast Asia. The areca nut has been classified as a "group one human carcinogen." Oral squamous cell carcinoma in the background of OSMF is one of the most common malignancies in South and Southeast Asian countries. Malignant transformation has been reported in 7%-12% cases of OSMF. Histopathological spectrum of OSMF includes the apparent alterations observed in the epithelium and connective tissue. Epithelial atrophy and sometimes epithelial hyperplasia with or without dysplasia are the peculiar alterations seen in the epithelium. In the connective tissue, there is extracellular matrix remodeling which results in excessive collagenization. Further cross-linking of collagen leads to hyalinization which makes the collagen resistant to proteolysis. Owing to fibrosis in the connective tissue, there is narrowing of blood vessels which further results in compromised blood supply to the local tissue milieu, that is, hypoxia. This tissue hypoxia elicits angiogenesis which may result in the malignant transformation of OSMF. Perpetual irritation of areca nut and its constituents to the oral mucosa leads to upregulation of pro-inflammatory cytokines and further juxtaepithelial inflammation. Thus, these coordinated reactions in epithelium and connective tissue leads the OSMF toward malignant transformation.

Evaluation of natural killer cell (CD57) as a prognostic marker in oral squamous cell carcinoma: An immunohistochemistry study.

OBJECTIVES: Natural killer (NK) cells are important effector lymphocytes. NK cells are considered to represent innate immune system. NK cells target and kill aberrant cells such as virally infected and tumorigenic cells. The purpose of this study was to assess the expression of CD57 in oral squamous cell carcinoma (OSCC) and to correlate the expression of CD57 with 3 years survival in patients with OSCC. MATERIALS AND METHODS: About 100 histopathologically diagnosed cases of OSCC of various grades were divided into two groups, i.e., Group I (dead patients) and Group II (live patients) from the archives of Department of Oral Pathology and Microbiology. CD57 was detected in these tissues by immunohistochemistry. RESULT: The results were analyzed using Spearman's correlation coefficient and students unpaired t-test. The mean CD57 labeling index in Group II was significantly higher than that found in Group I (P = 0.000). There was a significant correlation (P = 0.00) in the mean CD57 levels between Groups I and II and prognosis of patient. CONCLUSION: CD57 could be a good prognostic marker for OSCC patients.

The domino effect: Role of hypoxia in malignant transformation of oral submucous fibrosis.

INTRODUCTION: Oral submucous fibrosis (OSMF) is a precancerous condition predominantly seen in people of Asian descent. About 7-12% OSMF patients develop oral squamous cell carcinoma (OSCC). Morphological features of OSMF especially fibrosis suggests a possibility of the hypoxic environment in diseased tissues. Oral cancer usually develops from hyperplasia through dysplasia to carcinoma. Neovascularization and increased glycolysis, represent adaptations to a hypoxic microenvironment that are correlated with tumor invasion and metastasis. The adaptation of cells to hypoxia appears to be mediated via hypoxia inducible factor-1α (HIF-1α). HIF-1α is said to be associated with malignant transformation of epithelium in other sites. It appears that HIF-1α plays a significant role in both prostate and cervical carcinogenesis at early stages. We hypothesize that progression of OSMF and malignant transformation in the background of fibrosis mediates via HIF-1α either by up- or down-regulation of various such molecules. Therefore, the main objective of this study was to investigate the relationship between the expression of HIF-1α in OSMF, OSCC and OSCC with OSMF. AIM: To investigate the relationship between the expression of HIF-1α in OSMF, OSCC and OSCC with OSMF. MATERIALS AND METHODS: The study group consists of histopathologically diagnosed 20 cases of OSCC, oral submucous fibrosis and OSCC with OSMF each. The immunohistochemistry was carried out on neutral buffered formalin-fixed paraffin-embedded tissue sections by using the monoclonal antibody of HIF-1α. RESULTS: A rise in the expression of HIF-1α from OSMF to OSCC to OSCC with OSMF is observed.