Evaluation of Collagen in Leukoplakia, Oral Submucous Fibrosis and Oral Squamous Cell Carcinomas Using Polarizing Microscopy and Immunohistochemistry

Abstract

Objectives: Picrosirius red and MMP are capable of degrading extracellular matrix proteins, expressed in lesions such<br />as squamous cell carcinomas. The present study was undertaken with an aim to analyze and compare changes in collagen<br />using Picrosirius red staining under polarizing microscopy and immunohistochemical staining using anti MMP-13 in<br />samples of oral leukoplakia, oral submucous fibrosis and oral squamous cell carcinoma. Materials and Methods:<br />A total of 70 slides were prepared and divided into 3 groups. Group I comprised 10 slides of normal gingival tissue,<br />Group II 40 slides of potentially malignant disorders and Group III 20 slides of well differentiated oral squamous cell<br />carcinoma. Half the slides for each group were stained with Picrosirius red stain and the remainder with antibodies to<br />MMP-13. Rerults: In Group II, MMP-13 connective tissue expression was greater in OSMF as compared to leukoplakia.<br />Group III showed elevated expression among 70% of cases. Picrosirius red staining in Group II cases, showed higher<br />staining Yellow-Orange andGreen-Yellow mature fibers in OSMF than leukoplakia cases while in Group III, 50%<br />OSCC cases showed Green-yellow stained immature thin fibers. Conclusion: In future, therapeutic measures targeted<br />against MMP-13 may inhibit collagenolysis to some extent and delay spread of tumors. An easy and reliable method<br />to determine the state of the stroma in such cases may be Picrosirius red staining with polarizing microscopy.