This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on April 29, 2022.
Unlike diagnostic imaging tests, which are generally non-invasive or only minimally invasive, diagnostic procedures used to screen for diseases like cancer usually involve an analysis of tissue or blood, often from a biopsy.
At City of Hope, the procedures used in diagnosing cancer include those listed below.
During a biopsy, a doctor removes a sample of tissue or fluid from the body. A pathologist inspects the cells under a microscope to determine whether they are cancerous. If the cells are found to be cancerous, a biopsy may help determine whether the cancer began at the site of the biopsy or if it started somewhere else in the body and spread to the biopsy site.
Sentinel lymph node biopsy: This procedure is performed to see whether cancer has spread to the lymph nodes. First, your doctor performs a procedure known as lymph node mapping to identify which lymph nodes to remove. A blue radioactive dye is injected into the area where cancer is present. Sentinel lymph nodes usually absorb the dye after about an hour. At this point, your surgeon removes any that have turned blue and send them to the laboratory for examination. This is called an excisional biopsy.
Bone marrow biopsy: This cancer diagnostic test involves the removal of bone marrow with a long needle that enters the skin, passes through the muscle and extracts a sample from your bone. A bone marrow biopsy helps your cancer care team determine how well treatments for blood cancers like leukemia, lymphoma or multiple myeloma are working, as well as whether the cancer has spread.
Fine-needle aspiration: This type of biopsy uses a very fine, hollow needle that is connected to a syringe to remove a very small portion of tissue or fluid from your tumor in order to detect cancer.
Core needle biopsy: Using a needle that is a bit larger than that of a fine-needle aspiration, a cylinder of tissue is removed (about 1/16 inch in diameter and 1/2 inch in length) while you’re under local anesthesia.
Bronchoscopy technology is used to diagnose and stage certain cancers, such as lung cancer and esophageal cancer.
A cytology test examines cells through body fluids and tissues. These tests may be used to look for cancer when a patient is due for a regular screening or is experiencing symptoms.
For example, a urine cytology test may help diagnose urinary tract cancers, such as those of the:
Cytology tests include lumbar punctures and Pap smears.
A lumbar puncture, or spinal tap, is a procedure during which a needle is inserted into the lower part of the spinal column to remove a sample of cerebrospinal fluid. The fluid surrounds and protects the brain and spinal cord.
A lumbar puncture is performed to collect and test the cerebrospinal fluid for diseases, infections and conditions that affect the central nervous system, including:
A lumbar puncture may be used to measure the pressure of the cerebrospinal fluid. Additionally, it may be performed to inject medications into the spinal canal. Spinal anesthesia, contrast dye for an X-ray exam or chemotherapy drugs are medications that may be given via a lumbar puncture.
For the procedure, the patient’s back is cleaned with an antibacterial solution. A doctor then administers a local anesthetic to numb the area. Next, the doctor inserts a hollow, thin needle into the lower back in the space between two vertebrae. The patient must stay completely still while the needle is inserted. He or she may feel some pressure. The cerebrospinal fluid is then removed through the needle. About a tablespoon of fluid is collected and sent to a lab for testing. After the fluid is collected, the patient may receive medication through the lumbar puncture.
The procedure takes about 30 minutes to perform.
A Pap test, or Pap smear, is a test for cervical cancer or precancerous conditions of the cervix. The test is performed along with a pelvic exam in a doctor’s office or clinic.
For the test, a woman lies on an exam table with her knees bent and her feet in stirrups. A doctor or nurse practitioner then gently inserts a speculum and uses it to widen the patient’s vagina to examine the vagina and cervix. The doctor or nurse practitioner then obtains a sample of cells from the cervix, using a scraping tool or small brush. The sample is put into a small bottle or onto a slide and sent to a laboratory for analysis.
Pap tests take about five minutes to perform. Patients may experience slight discomfort and mild cramping.
Learn more about Pap tests and pelvic exams
Certain endoscopic procedures may be used to locate and diagnose cancer, particularly in the:
Anoscopy: This procedure is performed if abnormalities are found during a digital rectal exam (DRE). As an endoscopic test, an anoscopy reveals abnormalities through the use of a thin, lighted, flexible tube called an anoscope. The anoscope is lubricated and then placed a few inches into the rectum. The patient may experience some discomfort during the procedure. A tissue sample for a biopsy may be taken during an anoscopy. This diagnostic test helps to detect cancers of the anus or rectum. An anoscopy is similar to a colonoscopy, but a colonoscopy also examines the entire colon.
Esophagoscopy: This procedure involves the use of an esophagoscope, a thin tube with a lighted lens, to examine the esophagus. It may be used to help detect cancer of the esophagus as well as head and throat cancers.
Mediastinoscopy: The area between your lungs and behind your breastbone is referred to as the mediastinum. During a mediastinoscopy, the doctor uses a lighted instrument with a lens, called a mediastinoscope, in order to view your chest cavity. This diagnostic procedure may help detect cancers of the lung, thymus gland and esophagus, as well as lymphomas. Biopsies of the lymph nodes may be taken as well.
Colonoscopy: This procedure allows the doctor to examine the inside of your colon, anus and rectum in order to detect colon and rectal cancers in the early stages. A long, thin tube with a lighted lens is inserted into the rectum, and a biopsy of any suspicious areas may be taken.
Flexible sigmoidoscopy: Like a colonoscopy, a flexible sigmoidoscopy is used to detect colorectal cancers, but it’s a less invasive procedure that allows your doctor to view only about half of your colon. During a flexible sigmoidoscopy, a lighted tube is guided into the colon to help detect precancerous changes and abnormalities.
After a biopsy is collected, your tissue sample will be evaluated microscopically. These results—along with laboratory, imaging and other diagnostic testing—will be used to establish whether cancer is present, as well as the extent of the cancer, which helps determine treatment options.