Evaluation of Nuclear Parameters in Relation to Regional Lymph Node Involvement in Oral Squamous Cell Carcinoma: A Cytomorphometric Study

Background: Up-regulation of ribosome biogenesis encodes the factors related to carcinogenesis. It has been shown that the nucleus diameter and number of nucleoli increase from normal mucosa to oral squamous cell carcinoma (OSCC). The relationship between nuclear parameters and lymph node involvement in OSCC has not been established, yet. The aim of this study was to evaluate the nuclear parameters comprising nucleoli count and nucleus: nucleoli ratio in relation to regional lymph node involvement in OSCC. Methods: Thirty-four formalin-fixed, paraffin embedded sections from different histopathologic grades of OSCC were stained with methyl green-pyronin. Mean number of nucleoli and nucleus: nucleoli ratio were calculated in 100 tumor cells from 10 random selected fields and compared based on lymph node involvement. Results: Nucleoli count in cases with metastasis to regional lymph nodes was not significantly different from that in cases without regional lymph nodes involvement (P = 0.29). The difference of nucleus: nucleoli ratio in cases with and without lymph nodes involvement were not significant (P=0.52). No significant correlation was found between the nucleoli count and lymph node involvement (r=0.08, P=0.78). The correlation between nucleus: nucleoli ratio and lymph node involvement was significant (r=0.58, P=0.02). Conclusion: The nucleus: nucleoli ratio of tumoral cells in OSCC was correlated to lymph node involvement. Based on the results, nucleus: nucleoli ratio can potentially be a useful tool to determine the lymph node involvement in OSCC.