Determining the Type of Tongue Base Cancer
Only after a pathologist analyses some cells or actual pieces of tissue from the lesion will your doctor be able to tell you if you have cancer. Your doctor and pathologist should specialise in head and neck cancers because some benign (non-cancerous) lesions can look like cancer on a small biopsy.

It is very important in oropharynx cancer to know if it is associated with HPV. This can be determined from a biopsy by running some special tests, including looking for DNA of the virus or looking for certain proteins, such as P16, related to the virus. While we do know that patients with HPV-related oropharyngeal cancers have a better prognosis, we are not quite at the stage where we can treat them differently.

Squamous cell carcinoma: These are by far the most common oropharyngeal cancers. They arise from cells lining the oropharynx. They should be divided into two main types, depending on some cellular findings relating the cancer to the human papillomavirus (HPV positive versus HPV negative).
Squamous cell cancers of the oropharynx are typically given a grade by a pathologist after looking at the cells under a microscope. Grade means that the tumour falls on a scale from well differentiated (Grade I) to poorly differentiated (Grade IV). It is generally felt that the prognosis for a more well-differentiated cancer is more favourable.

More rarely, other cancers can be found in the oropharynx as well. Some of them include:
Salivary gland cancers: There are minor salivary glands located under the lining of the throat. Therefore, cancers that we typically see in salivary glands can arise in this region and they include diagnoses such as mucoepidermoid carcinomas, adenocarcinomas and adenoid cystic carcinomas, to name a few. See Salivary Gland Cancer for more information.

Lymphoma: The throat is lined with lymphoid cells. Some major sites of lymphoid tissue include the adenoids in the nasopharynx and palatine tonsils and lingual tonsils in the oropharynx. This is why lymphoma might appear as a lump in the throat area.

Mucosal melanoma: These cancers come from skin cells that give skin its color. In rare cases, melanoma can be found in the lining of the mouth, nose and/or throat.

Other rare cancers include:
 Sarcomas such as chondsarcoma, liposarcoma and synovial sarcoma
 Malignant fibrous histiocytoma
 Peripheral Neuroectodermal Tumour (PNET)
 Cancer spread from another site