Architectural Analysis of Picrosirius Red Stained Collagen in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma using Polarization Microscopy

Abstract

Introduction: Collagen degradation is important both for carcinogenesis and in its progression. Research regarding the co-relation of collagen with Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) is less explored.

Aim: To elucidate the nature of collagen in Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) using Picrosirius Red Stain (PSR) under polarizing microscopy.

Materials and methods: The study consisted of a total 40 samples which were divided into three groups. Group I included buccal mucosa as negative and irritation fibroma as positive control, group II consisted of OED and group III consisted of Oral Squamous Cell Carcinoma (OSCC). A histochemical analysis was conducted using PSR-polarization method by two independent observers.

Results: The control group shows predominantly reddish-orange birefringence. In OED with the advancement of grades, the colour changed from yellowish-orange colour to yellow-greenish with progressive increase in greenish hue. As OSCC regresses from well to poorly differentiated, the colour changed from reddish-orange to yellowish orange to greenish-yellow suggesting a transition from mature to immature collagen.

Conclusion: An observable gradual change in collagen of both OED and OSCC was noted as they were proceeding from benign to critical step. Thus, PSR is a useful tool for studying stromal changes as supporting collagen shows the transition in the form besides the alterations in epithelial cells.

Keywords: Birefringence; Greenish yellow; Reddish orange; Yellowish orange.

[Table/Fig-3]:

a) Photomicrograph of histologically normal buccal mucosa as negative control showing predominantly reddish-orange birefringence. (Picrosirius red stain, X100) b) Photomicrograph of buccal mucosa irritation fibroma as positive control showing reddish-orange colour. (Picrosirius red stain, X100) c) Photomicrograph of histologically normal buccal mucosa used as negative control (H&E stain, X100) d) Photomicrograph of buccal mucosa irritation fibroma used as positive control (H&E stain, X100)

[Table/Fig-4]:

a) Photomicrograph of Mild dysplasia showing predominantly yellowish orange colour with minimal areas of red birefringence. (Picrosirius red stain, X 100) b) Photomicrograph of Moderate dysplasia showing yellowish orange colour with greenish hue. (Picrosirius red stain, X 100) c) Photomicrograph of Severe dysplasia showing intense greenish hue. (Picrosirius red stain, X100) d) Photomicrograph of Mild dysplasia seen under a light microscope (H&E stain, X100) e) Photomicrograph of Moderate dysplasia seen under a light microscope (H&E stain, X100) f) Photomicrograph of Severe dysplasia seen under a light microscope (H&E stain, X100)

[Table/Fig-5]:

a) Photomicrograph of Well differentiated OSCC showing reddish orange birefringence. (Picrosirius red stain, X100) b) Photomicrograph of Moderately differentiated OSCC showing yellowish orange with sight greenish hue. (Picrosirius red stain, X100) c) Photomicrograph of Poorly differentiated OSCC showing greenish yellow colour. (Picrosirius red stain, X100) d) Photomicrograph of Well differentiated OSCC seen under a light microscope (H&E stain, X100) e) Photomicrograph of Moderately differentiated OSCC seen under a light microscope (H&E stain, X100) f) Photomicrograph of Poorly differentiated OSCC seen under a light microscope (H&E stain, X100)