What is the most common malignant neoplasm of the oral cavity?

Squamous cell carcinoma (SCC) accounts for over 90% of all oral cavity malignancies, making it by far the most common oral cancer. It arises from the squamous epithelium lining the oral mucosa. Common sites include the lateral/ventral tongue, floor of mouth, soft palate, and buccal mucosa. Major risk factors include tobacco use, alcohol consumption, and HPV infection (particularly for oropharyngeal SCC). Mucoepidermoid carcinoma and adenoid cystic carcinoma are the most common malignant salivary gland tumors. Melanoma is rare in the oral cavity.