Evaluation of immunohistochemical expression of epithelial- mesenchymal transition markers E-cadherin, Twist and Snail in oral submucous fibrosis and their possible association with malignant transformation.

BACKGROUND: Oral submucous fibrosis (OSMF) is a chronic, potentially malignant condition of the oral mucosa, predominantly seen in people of Asian descent. The reported malignant transformation rate of OSMF is 7%-13%. In the context of the understanding progression of OSMF, the study of prime molecular expressions is essential. Various markers have received more attention, one of them is E-cadherin. Various factors which promote epithelial-mesenchymal transition (EMT) and inhibit E-Cadherin include Snail1, Snail2, Twist and EF1/ZEB1. The intended study was undertaken to evaluate the possible role of E-cadherin and its regulatory markers Twist1 and Snail1 in OSMF. AIMS AND OBJECTIVES: To evaluate the expression of E-cadherin, Twist1 and Snail1 in OSMFTo evaluate their possible association with malignant transformation of OSMF. MATERIALS AND METHODS: Histologically proven 20 cases of each OSMF with and without dysplasia were taken as the study group, 20 normal mucosa as control group and were subjected for immunohistochemical (IHC) expression with E-cadherin, Twist1 and snail1. RESULTS: Immunohistochemical expression of all the three markers showed statistically significant expression of all the three markers. Intensity and percentage of staining between the groups were statistically significant for E-cadherin between normal oral mucosa (NOM) and OSMF with dysplasia (OSMFD), no significance was found between NOM and OSMF, whereas Snail1 and Twsit1 were statistically significant between NOM and OSMF and also between NOM and OSMFD. However, no significance was found for all the three markers when compared between the groups OSMF and OSMFD. CONCLUSION: The increased expression of Snail1 and Twist1 with concomitant loss of E -cadherin in OSMF suggests the role of the EMT.

Parosteal osteosarcoma: Report of a rare juxtacortical variant of osteosarcoma affecting the maxilla.

Parosteal osteosarcomas are rare, low-grade juxtacortical variant of osteosarcoma, especially in the jaws, representing 1.6% of all bony malignant tumours and upto 5% of all osteosarcomas. Only 12 cases of intraoral parosteal osteosarcomas have been reported in the English literature. In the jaws males are more commonly affected with peak occurrence at 39 years and nearly equal site predilection for maxilla and mandible. Radiographically, parosteal osteosarcomas are radiodense, lobulated masses with a broad stalk to the cortex of the bone with no periosteal reaction and medullary invasion. Microscopically, shows well-differentiated tumor with minimum atypia and rare mitotic figures separating trabeculae of woven bone. Unlike classical and periosteal osteosarcoma, it is considered to have a good prognosis. A case report of this rare entity in 22-year-old female patient with bony hard, painless swelling of 9 months duration in maxillary premolar-molar region is presented. The need for differential diagnostic approach is emphasized from other seemingly benign clinical entities.