ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. To see other pages, use the menu.
Doctors use many tests to find, or diagnose, cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the cancer has spread. Imaging tests show pictures of the inside of the body. Doctors may also do tests to learn which treatments could work best.
For most types of cancer, a biopsy is the only sure way for the doctor to know whether an area of the body has cancer. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.
This list describes options for diagnosing these types of cancer. Not all tests listed will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:
The type of cancer suspected
Your signs and symptoms
Your age and medical condition
The results of earlier medical tests
To make the diagnosis, a complete medical history and physical examination are necessary. During a physical examination, the doctor feels for any lumps on the neck, lips, gums, and cheeks. The doctor will also inspect the nose, mouth, throat, and tongue for abnormalities, often using a light and/or mirror for a clearer view.
Signs of nasal cavity and paranasal sinus cancer are often very similar to symptoms of chronic or allergic sinusitis. The physical examination is important, and doctors may perform 1 or more of the tests listed below to reach a diagnosis. There are no specific blood or urine tests that can be performed to help make an early diagnosis of either of these types of cancer.
Other diagnostic tests
In addition to a physical examination, the following tests may be used to diagnose nasal cavity or paranasal sinus cancer:
Biopsy. A biopsy  is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. A pathologist then analyzes the sample(s). A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease.
Endoscopy. An endoscopy  allows the doctor to see inside the body with a thin, lighted, flexible tube called an endoscope. The person may be sedated as the tube is inserted through the mouth or nose to examine the head and neck areas. Sedation is the use of medication to help a person become more relaxed, calm, or sleepy. This examination has different names depending on the area of the body that is examined, such as laryngoscopy, which examines the larynx; pharyngoscopy, which examines the pharynx; or nasopharyngoscopy, which examines the nasal cavity and nasopharynx.
In some cases, a diagnosis of paranasal sinus cancer will be made during endoscopic surgery for what is believed to be benign chronic sinusitis. Before completing the surgery, the surgeon should take a biopsy sample of healthy-looking tissue to confirm benign chronic sinusitis. This procedure is called a frozen section examination. For more information about surgery, see the Treatment Options  section.
X-ray. An x-ray is a way to create a picture of the structures inside of the body, using a small amount of radiation. An x-ray can show if the sinuses are filled with something other than air. If they are, the issue is usually not cancer but, instead, an infection that is treatable. If treatment doesn’t work to clear the sinuses, then other more specialized x-ray tests may be done to identify the blockage. Signs of cancer on an x-ray may be followed up with a computed tomography scan, also called a CT scan (see below).
Computed tomography (CT or CAT) scan. A CT scan  creates a 3-dimensional picture of the inside of the body using x-rays taken from different angles. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can also be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a liquid to swallow. CT scans are very useful in identifying cancer of the nasal cavity or paranasal sinus.
Magnetic resonance imaging (MRI). An MRI  uses magnetic fields, not x-rays, to produce detailed images of the body, especially images of soft tissue, such as the eye in its socket and the part of the brain near the sinuses. An MRI can also be used to measure a tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill to swallow.
Bone scan. A bone scan  may be done to see if cancer has spread to the bones. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark.
Positron emission tomography (PET) or PET-CT scan. A PET scan is usually combined with a CT scan (see above), called a PET-CT scan . However, you may hear your doctor refer to this procedure just as a PET scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive sugar substance is injected into the patient’s body. This sugar substance is taken up by cells that use the most energy. Because cancer tends to use energy actively, it absorbs more of the radioactive substance. A scanner then detects this substance to produce images of the inside of the body.
After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is cancer, these results also help the doctor describe the cancer. This is called staging.
The next section in this guide is Stages and Grades . It explains the system doctors use to describe the extent of the disease and how the cancer cells look under a microscope. Or, use the menu to choose another section to continue reading this guide.