Diagnosis
If you have any of the symptoms mentioned, especially a sore or ulcer in the mouth or lips that does not heal or causes pain or bleeding, please contact a doctor immediately. It may be necessary to see a physician who specializes in diseases of the head and neck. These physicians are trained to do specialized examinations of the head and neck and to diagnose cancer. This specialist will thoroughly examine the mouth, lips, gums, cheeks, tongue, neck, and possibly other nearby areas. The doctor will look for any sores, ulcers, loose teeth, or signs of cancer. The doctor may use small mirrors inserted into the mouth and a powerful light from a head lamp to examine the inside of the lips and oral cavity for any abnormalities. If the doctor notices any suspicious areas, a biopsy will be performed.
Biopsy
If any of these diagnostic tests indicate the presence of cancer, the doctor will conduct a biopsy to be certain. A biopsy is a procedure in which the doctor removes a tissue sample and a pathologist examines it under a microscope to determine if it contains cancer cells. A biopsy is the only way to be certain of a cancer diagnosis. The doctor may recommend the following types of biopsy, depending on the location and extent of the tumor:
Punch Biopsy
A punch biopsy is the most common biopsy procedure for lesions in the oral cavity. The doctor uses a special instrument with a circular blade to remove the cylinder of tissue from a suspicious area.
Incisional Biopsy
In an incisional biopsy, the doctor uses a surgical knife to remove the entire tumor or part of the tumor. The doctor then sends the tissue sample to a laboratory to determine if the tumor is benign or malignant.
Fine Needle Aspiration (FNA)
This test is not often performed on tumors of the lip and oral cavity, but may be recommended if a lump or mass is detected in the neck. In this case, the doctor will perform a needle biopsy to determine if the lymph node is cancerous.
Imaging Tests
Imaging tests produce pictures of the body and allow the doctor to determine if a tumor is present, as well as the size, location, and extent of the tumor. Imaging tests can also detect the spread of cancer into nearby structures.

Chest X-Ray
The doctor may recommend a chest X-ray to determine if the cancer has spread to the lungs or other organs in the chest.
Computed Tomography (CT) Scan
If symptoms or examination raise concerns for the presence of cancer, your doctor may order a CT scan. A CT scanner rotates around your body taking pictures, and produces detailed cross-sectional images of your body. It allows doctors to pinpoint the exact location of the tumor and check for cancer spread.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) uses radio waves and a powerful magnet to create clear and detailed images of body parts. Magnetic waves affect the spin of the elements in the cells of the body and that energy is then released in a characteristic pattern, which is translated by a computer in order to show "slices" of the body. This test is very useful for examining specific areas of the body, especially the soft tissues in the head and neck region.
Positron Emission Tomography (PET) Scan
For a PET scan, the doctor injects a radioactive substance into the patient's bloodstream, typically labeled sugar molecules. The sugars are collected in malignant (cancerous) cells at a much higher amount than in the rest of the patient's body. The doctor then uses a PET scanner to detect these areas of increased sugar uptake and to find locations concerning for cancer in the patient's body.

Barium Swallow
For this test, the patient drinks a chalky liquid called barium and undergoes a series of X-rays. The barium coats the lining of the throat and esophagus and clearly outlines it on X-rays, making it easy for the doctor to identify any abnormalities. The doctor may recommend this procedure if the patient has trouble swallowing, or to look for other cancers in these areas.