Myofibroblast Stromal Presence and Distribution in Squamous Epithelial Carcinomas, Oral Dysplasia and Hyperkeratosis

Purpose: Stromal elements play a key role in growth and development of different neoplasms. Myofibroblasts are the major components and occur in stromal tissue during carcinogenesis processes. The purpose of this study was to review the frequency and the distribution pattern of myofibroblasts(alpha SMA-positive) in the stroma of squamous epithelial carcinoma and to compare values with those for with oral dysplasia and hyperkeratosis. Methods: we evaluated alpha SMA protein frequency in hyperkeratosis (N = 18), oral epithelial dysplasia (N = 18) and oral squamous cell carcinoma (N = 18) using immunohistochemistry. Results: alpha SMA-positive expression was observed in 67% of OSCC tissue samples with network and spindle patterns, whereas it was seen in 22% with a focal pattern in dysplasia and in 6% with a scanty pattern in hyperkeratosis cases. Conclusion: These findings suggest that an increase in number of myofibroblasts and change in their distribution pattern occurs during carcinogenesis which can be an expression of their role in tumor invasive characteristics.