Cytomorphometric Analysis of Oral Premalignant and Malignant Lesions Using Feulgen Stain and Exfoliative Brush Cytology

Objective: Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide and accounting for 90% of cancers of oral cavity. Tobacco abuse has been proved to be the major risk factor in the development of OSCC. Despite advances in surgery, radiation and chemotherapy, the five year survival rate for oral cancer has not improved significantly over the past several decades and it remains at about 50 to 55%. Cytobrush sampling is more frequently used nowadays for exfoliative cytology, since it maximizes the number of cells obtained, and facilitates their uniform distribution onto the microscope slide, thus probably improving sensitivity.Our study was therefore carried out to analyze the cytomorphometric features of cells obtained by cytobrush and stained with Feulgen stain from oral premalignant and malignant lesions and to find out whether these features could be used to detect dysplasia and malignancy in their early stages. To analyze the cytomorphological features of cells in smears of oral premalignant and malignant lesions obtained from exfoliative brush cytology using Feulgen stain and to assess the efficacy of the same in detecting dysplasia and malignancy. Materials and Methods: Our study comprised of clinically and histopathologically diagnosed sixty cases which were grouped into twenty cases each of tobacco users with lesions (Leukoplakia and Erythroplakia) (Group I); tobacco users without lesions (Group II); Oral squamous cell carcinoma (OSCC) lesions (Group III); and normal mucosa (Group IV). The epithelial cells from the lesion were collected with a cytobrush and smears were stained with Feulgen stain. The cells were measured using software for their nuclear area, nuclear diameter, cellular area, cellular diameter and nuclear to cellular area ratio (N:C). Results: The exfoliated cells showed similar alterations as those occuring in histopathological sections of premalignant and malignant lesions. The N:C ratio, mean nuclear area and diameter value was highest in Group III and lowest in Group IV. The mean cellular area and diameter was highest in Group IV and lowest in Group III. Tukey-HSD formula for pairwise comparison showed a significant difference in mean values of nuclear and cellular area and diameter and N:C ratio between all the groups except in Group I and Group III. Conclusions: Our study was able to differentiate dysplastic and malignant cells from normal ones using analysis based on nuclear and cellular parameters. We therefore conclude that cytomorphometric analysis using exfoliative brush cytology can be of great value for monitoring and follow up of suspicious lesions and can provide an excellent additional diagnostic test for detecting early oral malignancy.