Diagnostic procedures

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.

The procedures we use in diagnosing cancer include those listed below.


An anoscopy 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.


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.

Learn more about biopsies


Bronchoscopy technology is used to diagnose and stage certain cancers, such as lung cancer and esophageal cancer.

Learn more about bronchoscopy

Endoscopic procedures

Certain endoscopic procedures may be used to locate and diagnose cancer, particularly in the esophagus, colon, rectum, stomach and chest.

Learn more about endoscopic procedures

Lumbar puncture

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:

  • Meningitis
  • Cancer (e.g., brain cancer, spinal cancer, leukemia)
  • Bleeding around the brain or spinal cord
  • Inflammation of the brain, spinal cord or bone marrow
  • Multiple sclerosis
  • Reye syndrome
  • Guillain-Barré syndrome
  • Neurosyphilis
  • Headaches of unknown cause

Lumbar punctures may also be used to measure the pressure of the cerebrospinal fluid. Additionally, they 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.

Pap test and pelvic exam

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