Detection of Apoptosis in Leukoplakia and Oral Squamous Cell Carcinoma using Methyl Green Pyronin and Hematoxylin and Eosin

Background & Objective: Cell population and turnover are controlled by a balance between cell proliferation and apoptosis. Detection of apoptosis in oral cancer contributes to its better prognosis and improved management. This study aimed to quantify apoptotic cells in leukoplakia and oral squamous cell carcinoma (OSCC) using methyl green-pyronin (MGP) and hematoxylin and eosin (H & E) staining. Methods: The sample included a total of 130 subjects (comprising 108 males and 22 females). Formalin fixed and paraffin embedded tissues were used and categorized into three groups of normal oral mucosa (n=10), leukoplakia with dysplasia (n=60), and OSCC (n=60). The number of apoptotic cells and apoptotic index (AI) were calculated after staining with MGP and routine H & E stained slides. Results: MGP stained the condensed chromatin of apoptotic cells. Statistically significant difference (P≤0.001) was observed among various study groups in terms of numbers of AI and apoptotic cells. Also, AI increased with increasing grades of dysplasia, and it was the highest in well differentiated OSCC. Results were statistically significant in both H & E and MGP stained sections (P≤0.001). A good correlation was found between MGP and H & E staining results. Conclusion: MGP is more specific and can lead to intense staining for chromatin in apoptotic cells. Accordingly, it can provide a good alternative to H&E; in identifying apoptotic cells.