Background: In a developing country like India, Oral cancer is a major health issue, representing the leading cause of death. Objective: Study the spectrum of premalignant and malignant lesions with grading of malignant lesions of oral cavity and to study the incidence of malignant and premalignant lesions of the oral cavity in relation to age, sex, and site of the lesion. Methods: The study was conducted for a period of 2 years, in the Department of Pathology, KVG Medical College and Hospital, Sullia. 100 oral biopsies received from the Surgical, Medical and Dental outpatient departments were studied. Clinical details were obtained from the requisition form. Biopsies received were processed and stained with H&E. Histopathological diagnosis regarding type and differentiation was made. Data was entered and analyzed using Microsoft excel 2007 and SPSS Version 17. Quantitative data was expressed as mean and standard deviation, Qualitative data was expressed as percentage and proportions. Results: Among 100 oral cavity lesions studied, 16% were premalignant and 84% were malignant lesions. Peak incidence was seen in 6th decade with a male preponderance. 43% of patients were smokers, 30% were habituated to smokeless tobacco. The commonest site in both the premalignant and malignant lesions were Buccal mucosa. Majority of cases (50%) of leukoplakias were associated with mild dysplasias, one case of erythroplakia showed mild dysplasia. Amongst the 84 malignant lesions, 78 cases were Squamous cell carcinoma and majorities (60.25%) were well differentiated. Maximum number of cases (63.63%) were seen in Stage I and II. Nodal metastasis was seen in 36.36%, perineural invasion in 27.2% and microvascular invasion was seen in 18.18% cases. Negative surgical margins were seen in 100% cases. Conclusion and Interpretation: A detailed clinical work up with histology can help in early detection of dysplastic and malignant changes and thus reduce morbidity and mortality due to malignant lesions.

Keywords: Erythroplakia; Leukoplakia; Squamous Cell Carcinoma; Verrucous Carcinoma.