Evaluation of extracellular matrix changes among oral submucous fibrosis and oral squamous cell carcinoma patients of Malwa region of Punjab using special histochemical stains: An insight into cancerous transformation

BACKGROUND: To assess extracellular matrix changes among oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC) patients using special histochemical stains. MATERIALS AND METHODS: Twenty biopsy specimens of OSMF and 30 biopsy specimens of OSCC were included in the present study. Among 20 OSMF specimens, 10 were of early OSMF and the remaining 10 were of advanced OSMF. Out of 30 OSCC specimens, 10 cases each were of well-differentiated OSCC, moderately differentiated OSCC and poorly differentiated OSCC. Three sections, each 4 μm thick, were obtained from all specimens. One section was stained with routine H&E staining, whereas the other section was stained with Masson’s trichrome (MT) stain for collagen and Verhoeff–Van Gieson (VVG) for elastic fibres. Evaluation of all specimens was performed under the light microscope. The arrangement of collagen fibres and elastic fibres was compared between the OSMF group and OSCC group, in between different grades of OSMF and in between different grades of OSCC. The results were evaluated using SPSS software. RESULTS: Early OSMF cases were associated with fibrosis in the superficial lamina propria, whereas advanced OSMF had fibrosis involving deeper muscle fibres. In all early OSMF cases, elastic fibres were arranged in thin bundles, whereas in advanced OSMF cases, elastic fibres were in thick bundles. In well- and moderately differentiated OSCCs, the collagen fibres were arranged in thick bundles and in poorly-differentiated OSCCs, the collagen fibres appeared to be fragmented. The elastic fibres in well-differentiated OSCC and moderately-differentiated OSCC were thickly arranged, and poorly-differentiated OSCC showed thin fibres and 70% of cases showed the absence of elastic fibres. CONCLUSION: Changes observed in both collagen and elastic fibres in the extracellular matrix (ECM) can be taken as a study model to further understand the progression of OSMF to OSCC using histochemical stains.