<prompt> Most common site of squamous cell carcinoma:Floor of the mouthTongueBuccal mucosaLip  <response>: Lateral border of tongue is the most common site of squamous cell carcinoma.Carcinoma of the tongue accounts for more than 50 of intraoral cancers in the United States. Two-thirds of lingual carcinomas appear as painless, indurated masses or ulcers of the posterior lateral border; 20 occur on anterior lateral or ventral surfaces, and only 4 occur on the dorsum. For unknown reasons, the oral tongue represents an increasingly common site of involvement in young patients. 