Introduction: Oral squamous cell carcinoma (OSCC) is the most common malignancy of oral cavity
with a high mortality rate. Myofibroblast in the stroma of malignant tumor is one of the main factors that
accelerates and modulates tumor progression and invasiveness.
Objectives: The current study aimed to investigate the presence of myofibroblasts in reactive oral lesion and
OSCC and to compare its staining in superficial and deep layers in different histological grades.
Patients and Methods: The study included the archival tissues of 30 OSCCs and 30 oral reactive lesions. The
myofibroblast was assessed in superficial and deep layers by immunohistochemical study of alpha smooth
muscle actin (α-SMA). Data were analyzed by SPSS software using chi-square, Kruskal-Wallis, and MannWhitney U tests. P<0.017 was considered to be statistically significant.
Results: The results revealed that presence of myofibroblasts was significantly higher in OSCCs compared
to oral reactive lesions (P=0.0001). The results also showed that myofibroblasts presented more in the deep
layers than in the superficial layers of OSCC (P=0.0001). A statistically significant difference was observed
in myofibroblasts among different histological grades of oral squamous cell carcinoma (P=0.0001).
Conclusion: The findings highlight that the presence of myofibroblast in the stroma, assessed by α-SMA,
indicates tumor progression and invasiveness in the patients with OSCC.