Analysis of cell proliferation rate in Oral Leukoplakia and Oral Squamous Cell Carcinoma

Objectives: Assessment of the cell proliferation rate in tissues can be one of the markers for impending malignancy in precancers. The state of activation and the proliferation activity of the cells can be assessed by the frequency of silver stained Nucleolar Organiser regions (AgNOR) within the nuclei which is significantly higher in malignant cells. The present study was carried out to analyze the distribution of the AgNOR in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC), and in their various histological grades, and to assess if the AgNOR distribution could give information on the malignant potentiality in premalignant lesions and aggressiveness of the malignant lesions. Study design: The study specimens comprised of 35 archival cases, of which 15 cases were of OL and 20 cases of OSCC. The specimens were stained by hematoxylin and eosin and modified silver staining method of Ploton et al. for the Nucleolar Organiser Regions. The specimens were analyzed independently by the two observers and was further statistically analysed. Results: The mean AgNOR count in OL was 2.80 ±0.50 and in cases of OSCC was 5.71± 1.08. The mean AgNOR count in OL cases of mild dysplasia was 2.59 ±0.66, in moderate dysplasia was 2.92± 0.43 and in severe dysplasia was 2.79. The mean AgNOR count in cases of well differentiated OSCC was 5.73± 1.62 and in cases of moderately differentiated OSCC was 5.67±1.19. Conclusion: The mean AgNOR count was higher in cases of OSCC as compared to cases of OL, and the AgNOR counts increased with the increase in the grades of dysplasia indicating a higher proliferative rate with increase in dysplasia.