Correlation between histological grading and ploidy status in potentially malignant disorders of the oral mucosa: A flow cytometric analysis

J Oral Maxillofac Pathol. 2013 May;17(2):169-75. doi: 10.4103/0973-029X.119747.

Abstract

Background: Histopathological grading of oral dysplastic lesions is the method of choice for evaluating malignant and potentially malignant disorders. Owing to inter- and intra-observer variability, determination of the DNA ploidy status of lesions may serve as an adjunct in the prediction of malignant transformation.

Aim: To correlate histopathological grading and ploidy status in potentially malignant and malignant disorders of the oral mucosa.

Settings and design: A pilot study was done with 30 patients (10 patients with oral potentially malignant disorders predominantly leukoplakia, 10 patients with oral malignant lesions and 10 patients with normal mucosa).

Materials and methods: Incisional biopsy was done after isolating the biopsy site with 1% Toluidine blue staining. Two sections of the tissue were removed and sent for histopathological and Flow-cytometric analysis respectively. Histopathological diagnosis was obtained and compared with Flow-cytometric results which were graded as diploid and aneuploid. Further, the S - phase fraction, DNA index were also calculated to evaluate the severity of malignant transformation or malignancy.

Statistical analysis: The results were analyzed using Pearson Chi-Square Test.

Results: There exists a significant correlation between histopathology and ploidy status in both potentially malignant and malignant group. (P = 0.002).

Conclusion: The data from this study has shown that DNA Ploidy analysis can be used as a valuable tool in assessing the carcinomatous progression of potentially malignant and malignant lesions.

Keywords: Deoxyribonucleic acid index; S-phase fraction; flow cytometer; histopathology; oral cancer; potentially malignant disorder.