There are many types of tumors that can develop on the lips or in the mouth. Oral cancers are categorized by where the cancer occurs in the oral cavity. They include the following:

• Lip cancer. Occur far more commonly in men than women. Most lip malignancies are squamous cell cancers. People with light skin or with prolonged sun exposure are more prone to develop lip cancers.
  
  
• Cancers of the floor of the mouth. The floor of the mouth is U–shaped and bounded by the lower gum and the tongue. Cancers in this area are usually malignancy cell cancers and typically occur in the front, middle area of the mouth.
  
  
• Tongue. Almost all tongue malignancies are squamous cell cancers, usually occurring on the side or the underside of the tongue. A condition called leukoplakia (formation of white patches) is common on the tongue. 
  
  
• Cancer of the cheek. The lining of the inside of the cheek (buccal mucosa) is a rare site for oral cancer, especially in the United States. It is common in countries where people chew tobacco mixed with betel leaves, areca nut and lime shell.
  
  
• Gum (gingiva) and hard palate cancers. Cancers of the lower gum are usually squamous cell cancers. In the upper gum and hard palate area (including behind the wisdom teeth), cancers in these areas can be squamous cell or some other type of cancer.
  
  
• Minor salivary gland cancer. This cancer can develop in the glands that are located throughout the mucosal lining of the mouth and throat. There are several types of salivary gland cancer, including:
  
  
• Adenoid cystic carcinoma
• Mucoepidermoid carcinoma
• Polymorphous low–grade adenocarcinoma