Doctors use many tests to diagnose cancer and find out if it has metastasized. Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. A biopsy is the removal of a small amount of tissue for examination under a microscope. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
- Age and medical condition
- Type of cancer suspected
- Type of symptoms
- Previous test results
The earlier bladder cancer is found, the better the chance for successful treatment. However, there is not yet a test that is accurate enough to screen the general population for bladder cancer, so most people are diagnosed with bladder cancer once they have symptoms . As a result, some patients have later stage disease when the cancer is first found, although most people diagnosed have noninvasive bladder cancer.
The following tests may be used to diagnose and learn more about the extent of bladder cancer:
Urine tests. The doctor tests a urine sample to find out if it contains tumor cells. If a patient is undergoing a cystoscopy (see below), an additional test may be performed that involves rinsing the bladder and collecting the liquid through the cystoscope or through another small tube that is inserted into the urethra. The sample can be tested in a variety of ways. The most common way is to look at the cells under a microscope, called urinary cytology. Urine passed out of the body during normal urination can also be examined by cytology. There are other urine tests using molecular analysis that can be done to help find cancer, usually at the same time as urinary cytology.
Cystoscopy  and TURBT. This is the key diagnostic procedure for this disease. It allows the doctor to see inside the body with a thin, lighted, flexible tube called a cystoscope. Flexible cystoscopy is performed in the doctor's office and does not require an anesthetic (medication that blocks the awareness of pain). This short procedure can detect growths in the bladder and determine the need for a biopsy or surgery.
If abnormal tissue is found, the doctor will do a biopsy . This procedure is called a transurethral bladder tumor resection or TURBT. During a TURBT, the doctor can remove the tumor and a sample of the bladder muscle near the tumor. A TURBT is used to diagnose bladder cancer and find out how deeply it has grown into the layers of the bladder. After the TURBT is done, the urologist will also evaluate the bladder to see if any masses can be felt. This is called an exam under anesthesia or EUA. The sample removed during the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A TURBT is also a treatment for a non-muscle-invasive tumor (see Treatment  for more information).
Computed tomography (CT or CAT) scan . A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows abnormalities or tumors. Sometimes, a contrast medium (special dye) is injected into a patient’s vein to provide better detail. The patient should tell the staff giving this test beforehand if he or she is allergic to iodine or other contrast mediums.
Magnetic resonance imaging (MRI) . An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture.
Find more about what to expect when having common tests, procedures, and scans .
After these 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 . Learn more about the first steps to take after a diagnosis of cancer .