Although there are several types of malignant oral cancers, more than 90 percent of all diagnosed oral cancers are squamous cell carcinoma.
Squamous cell carcinoma
Also known as squamous cell cancer, this type of cancer originates in the squamous cell layer in the lining of the oral cavity and oropharynx. In the early stages, this cancer is present only in the lining layer of cells (called carcinoma in situ). When the cancer spreads beyond the lining, it is called invasive squamous cell cancer.
Although also considered a type of squamous cell carcinoma, this low-grade cancer rarely metastasizes (spreads to distant sites). Comprising less than 5 percent of all diagnosed oral cancers, verrucous carcinoma can spread deeply into surrounding tissue, requiring surgical removal with a wide margin of surrounding tissue.
Minor salivary gland cancers
The lining of the oral cavity and oropharynx contains numerous salivary glands. Sometimes cancer will originate in a salivary gland. Treatment depends on the type and location of the salivary gland cancer, as well as the extent of spreading. According to the ACS, salivary gland cancers are rare.