Diagnosis of oral cancer is done on the basis of history and findings of physical examination. If your doctor suspects any lesion in your oral cavity as a possible cancerous growth then he or she will recommend tests.
Biopsy: This is the first test that will be done if oral cancer is suspected. Biopsy is an invasive medical procedure in which a sample of tissue or cell is taken to be examined by a pathologist, usually under a microscope. Tissue sample for biopsy can be obtained in many different ways. You will be referred to an oncologist (a doctor who specialises in the treatment of cancer) or an ear, nose and throat (ENT) specialist for diagnosis and treatment.
The three main methods used to do biopsy in cases of suspected mouth cancer are:
Punch biopsy: In this type of biopsy, a special surgical instrument or knife is used to take sample of tissue from the suspected area in an easily accessible place (such as tongue, cheek) in the mouth. Since it is a painful procedure you will be given a local anaesthetic to numb the area.
Needle biopsy: If the sample of tissue has to be taken from organs or from lumps that are below the surface of the skin needle biopsy may be used. It can be done using a fine-needle aspiration (FNA) biopsy or core needle biopsy (CNB). A fine needle aspiration (FNA) is done if any swelling in your neck is suspected to be because of oral cancer. A local anaesthetic is given before the procedure so that you don't feel any pain or discomfort.
Panendoscopy: It is used to obtain sample of tissue when the suspected lesion is at the back of your throat or inside the nasal cavity. A special instrument called a panendoscope (an instrument with long thin tube that contains a camera and light source) is used to take a sample. The instrument can also help to see if the cancer has spread from your mouth to other structures, which are not seen on direct visual examination such as your larynx (voice box), oesophagus (gullet) or trachea (windpipe).
If the lesion or growth shows presence of cancer in biopsy then tests will be done to stage the disease, i.e. check how far the cancer has spread. Some tests that may be done to stage the cancer include imaging studies such as X-ray, magnetic resonance imaging (MRI) scan and computerised tomography (CT) scan. If needed a positron emission tomography (PET) scan may be done. Staging helps to determine the spread of disease and plan treatment.