Stromal myofibroblasts in oral squamous cell carcinoma and potentially malignant disorders.

INTRODUCTION Concurrent with the progression of a non- diseased epithelium to the pre-cancerous epithelium to carcinoma, the stroma also undergoes modifications. Myofibroblasts are important stromal cells that play a crucial role in carcinogenesis. The current study investigated the presence of myofibroblasts in healthy oral mucosa, potentially malignant disorders (PMDs) and squamous cell carcinoma (SCC). MATERIALS AND METHODS The study material consisted of a total of 106 samples categorized into three groups, namely, Group I - Oral SCC (OSCC) (n = 42), Group II - PMDs (n = 32) and Group III - Oral healthy mucosa (n = 32) subjected to immunohistochemical analysis using alpha Smooth Muscle Actin. RESULTS Among the 42 cases of OSCC, the staining index was negative in 23 cases (54.7%), low in 9 cases(21.4%) and moderate in 10 cases (23.8%). The stroma of cases of verrucous carcinoma, cases of Hyperkeratosis with epithelial dysplasia, 77.5% of the cases of oral Submucous Fibrosis (OSMF) and healthy oral mucosa were devoid of myofibroblasts resulting in a grade of "0" in all cases.Two of the cases of OSMF (12.5%) showed low staining index for myofibroblast. There was a significant difference in the myofibroblasts expression between the Groups (Kruskal-Wallis test P<0.001). CONCLUSION The findings of the current study justify "myofibroblast" as one among the key stromal element in tumor progression. Future studies involving a larger sample size along with follow up of patients with PMDs are essential to identify the exact stage in which they emerge in the stroma of these lesions.