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Background: Solid tumors such as oral squamous cell carcinoma (OSCC) are composed of malignant epithelial cells and the stroma in which these cells are dispersed. As the tumor progresses, the extracellular matrix undergoes dramatic morphological and architectural changes. Special stains make analysis easy and less erroneous by highlighting the area of interest and can be used to study these changes. Aim: The aim of the study was to analyze morphological changes in collagen fibers in various histological grades of OSCC using Masson's trichrome (MT) and Picrosirius red (PSR). Study Design: The study comprised 74 tissue samples, divided into two groups: Group I consisted of 63 cases of histologically proven OSCC (39 cases of well-differentiated squamous cell carcinoma [WDSCC], 17 moderately differentiated squamous cell carcinoma [MDSCC] and 7 poorly differentiated squamous cell carcinoma [PDSCC]) and Group II consisted of 11 cases of normal mucosa as controls. Materials and Methods: Sections were stained with hematoxylin and eosin, MT and PSR and observed under light and polarizing microscope, respectively. Statistical Analysis: ANOVA, Tukey's honestly significant difference post hoc multiple comparison test, Chi-square test and paired t-test were used for the statistical analysis. Results: As the grade of OSCC progressed, collagen fibers became thin, loosely packed and haphazard. The mean area fraction also decreased. They exhibited orange–red hue and strong birefringence in WDSCC, yellowish-orange hue and strong birefringence in MDSCC and greenish-yellow hue and weak birefringence in PDSCC. Conclusion: Initially, there is a reorganization of the collagen fibers in an attempt to prevent the invasion of tumor cells, but as cancer progresses, the stromal change enhances movement of the tumor cells within it, leading to metastasis.

Background: Odontogenic keratocyst (OKC) and orthokeratinized odontogenic cyst (OOC) show considerable difference in biological behavior, and the study of the organization of collagen fibers may be helpful in understanding the nature of these variants. Aims: The purpose of this study is to determine the clinicopathological features and to analyze the birefringence of collagen fibers in OKC and OOC using picrosirius red stain to delineate its exact role in biological behavior. Materials and Methods: Clinical data were obtained from the case records of 71 patients, and for the analysis of birefringence, paraffin-embedded blocks of 10 cases each of OKC and OOC were retrieved from the archives of our department during the period of 2010–2018. Tissue sections were obtained and stained with picrosirius red stain to determine the birefringence of collagen fibers in both the variants. Statistical analysis was done by unpaired t-test. Results: Out of 71 cases, 61 were OKC and 10 were OOC. The clinicopathological data revealed that the most common affected age group was third decade with male predilection and the most common site noted was posterior mandible, and considerable difference in birefringence was noted in the collagen fibers of OKC and OOC. Conclusion: The study results analyzing the clinicopathological parameters of OKC and OOC could act as a viable record for the distribution of odontogenic lesions in the sample population. Significant differences in birefringence were demonstrated in OKC and OOC, suggesting that different collagen fibers may exist in the two lesions.

Background: Odontogenesis is a highly coordinated and complex process which depends on cell–cell interactions that result in initiation and generation of tooth. Tissue remnants of developing tooth can form odontogenic tumors possibly, reflecting different developmental stages in tooth formation. In both odontogenesis and odontogenic tumors, stroma plays a prominent role in maintaining epithelial tissues with continuous molecular interactions. As the collagen forms an integral part of connective tissue stroma, in the present study, polarization colors and thickness of the collagen fibers were assessed in both tooth germ papillae and ameloblastoma using picrosirius red (PSR) stain. Materials and Methods: Collagen fibers in 20 cases of ameloblastoma and 10 tooth germs from the human fetus were evaluated with PSR stain and examined under polarizing microscopy. Results: Polarization colors of red-colored collagen fibers with greater diameter were more in ameloblastoma when compared to tooth germ papillae in which green-colored collagen fibers with smaller diameter being more. Conclusion: The absence of hard tissue formation in ameloblastoma might be due to the presence of significantly more number and greater thickness of red-colored collagen fibers. Thus, the nature of collagen fibers can predict the nature in terms of biologic behavior and prognosis.

Background: Many studies have been carried out to study the role of extracellular matrix proteins, growth factors and matrix metalloproteinases on tumor invasion. However, literature related to the analysis of connective tissue fibers in varying grades of oral squamous cell carcinoma (OSCC) is very limited. Aim: To analyze the changes in collagen and elastic fibers in varying grades of (OSCC). Settings and Design: This retrospective study was carried out using a light and polarizing microscope. Materials and Methods: Three sections each were cut from fifty samples of varying grades of OSCC and ten samples of control followed by staining with H and E, Picrosirius-Red and Verhoeff-Van Gieson. Qualitative and quantitative analysis of collagen and elastic fibers were accomplished using set criteria. Statistical Analysis: Data were entered into the Statistical Package for Social Sciences (SPSS) version 13.5 for analysis. Results: A change in colors of collagen fibers was seen on progressing from well to poorly differentiated OSCC. Thin collagen fibers predominantly exhibited greenish yellow, but the thick fibers exhibited a variety of colors. As the grade of OSCC progressed, collagen fibers were loosely packed haphazardly arranged. Statistically insignificant results were obtained for quantitative analysis of collagen and qualitative analysis of elastic fibers. Conclusion: The collagen fibers undergo a change in color, orientation and packing in the stroma of varying grades of OSCC. The uniqueness of this study lies in the exploration of elastic fibers in OSCC which has not been done so far.

Background: Oral submucous fibrosis (OSMF) is considered as a potentially malignant disease, which is associated with betel quid and pan masala chewing. It is thought to be due to the defective collagen synthesis and degradation. The amount of collagen in the diseased varies with the functional stages and histopathological grades of the disease. Aims: The aim of the study was to assess the severity of the disease in oral submucous fibrosis, by correlating the functional staging with the histopathological grading and analyze the collagen distribution in different grades of OSMF using picrosirius red stain under polarizing microscope and also to assess the quantitative changes in collagen with respect to various histopathological grades of OSMF using spectrophotometry. Materials and Methods: The study conducted on 40 subjects, which included 30 subjects with different functional and histopathological grades of oral submucous fibrosis (OSMF), and 10 were in control group. Functional staging and histopathological grading was done based on the definite criteria. A Histopathological and quantitative analysis of collagen was conducted using picrosirius red stain, polarizing microscope and spectrophotometer, respectively. The results were analyzed using chi-square test, and the significance was tabulated. Results: The functional staging and the histopathological grading did not show statistical correlation, but as the histopathological grade of the disease increased; there was a shift in the polarizing color from yellow-green to orange-red. In the colorimetric estimation, the optical densities of the sample decreased as with increased grades of OSMF. Conclusion: In the present study, we observed that the histopathological grading of OSMF is not correlating with the functional staging of OSMF. Therefore, it mandates the proper correlation between the functional staging and the histopathological grading before the commencement of the treatment to render better outcome of the treatment.

Background: Oral submucous fibrosis (OSF) is a precancerous condition in which there is excessive deposition of collagen in connective tissue. The purpose of present study was to compare changes in birefringence of collagen fibers in histopathological stages of OSF. Materials and Methods: Collagen in connective tissue of 91 cases of OSF was studied by staining 5 μm thick sections with picrosirius red. The polarization colors of thin (0.8 μm or less) and thick (1.6-2 μm) collagen fibers were recorded. Results: The birefringence of thin collagen fibers showed no difference in both histopathological connective tissue stages and degrees of epithelial dysplasia. The polarization colors of thick collagen fibers showed a gradual change from predominantly yellow-orange to greenish-yellow in advancing connective tissue stages and degrees of epithelial dysplasia. Conclusion: The results of present study show a significant change in birefringence of collagen between connective tissue stages and between mild, moderate to severe degree of epithelial dysplasia. This change in birefringence colors and arrangement of collagen fibers may give an implication of impending neoplastic change in OSF.

Objective : The aim of the study was to assess the severity of the disease in oral submucous fibrosis (OSF), correlate the clinical, functional staging with histopathological staging, and analyze collagen distribution in different stages of OSF using the picrosirius red stain under polarizing microscopy. Materials and Methods : The study included randomly incorporated 50 subjects, of whom 40 were patients with OSF, and 10 were in the control group. Clinical, functional staging in OSF cases was done depending upon definite criteria. A histopathological study was conducted using the hematoxylin and eosin stain and picrosirius red stain. Collagen fibers were analyzed for thickness and polarizing colors. Furthermore, clinical, functional, and histopathological stages were compared. Statistical Analysis : Descriptive data which included mean, SD, and percentages were calculated for each group. Categorical data were analyzed by the chi-square test. Multiple group comparisons were made by one-way ANOVA followed by Student's t-test for pairwise comparisons. For all tests, a P-value of 0.05 or less was considered for statistical significance. Results : As the severity of the disease increased, clinically, there was definite progression in subjective and objective symptoms. Polarized microscopic, examination revealed, there was a gradual decrease in the green-greenish yellow color of the fibers and a shift to orange red-red color with increase in severity of the disease. Thereby, it appeared that the tight packing of collagen fibers in OSF progressively increased as the disease progressed from early to advanced stages. We observed that the comparison of functional staging with histopathological staging was a more reliable indicator of the severity of the disease. Conclusion : In the present study, we observed that mouth opening was restricted with advancing stages of OSF. The investigation also points to the importance of assessing the cases of OSF, especially with regard to functional and histological staging in planning the treatment.