For a transrectal prostate biopsy, an ultrasound probe is inserted into the rectum. Guided by ultrasound, a spring-loaded needle is used to take samples from the prostate through the rectal wall. A transperineal prostate biopsy is less common. This type of biopsy also takes prostate samples, but through a cut made in the perineum, the area between the scrotum and anus.
While ultrasound is often used to guide the sampling, other ways of imaging such as MRI or CT scans may also be used.
A prostate biopsy may be done:
Why It Is Done
You may need a prostate biopsy if your doctor found something of concern in your lab work or during your exam. A biopsy can help find out if you have prostate cancer. It may also be done for other reasons, such as monitoring the growth of prostate cancer for someone on active surveillance.
How To Prepare
If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your procedure. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.
Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your procedure. Your doctor will tell you if you should stop taking any of them before the procedure and how soon to do it.
Most prostate biopsies are done with local anesthesia. But if you are having general anesthesia, you will need to have someone to take you home, since anesthesia will make it unsafe for you to drive or get home on your own. Some pain medicines can also make it unsafe for you to drive.
How It Is Done
Some people have a prostate imaging test, such as an MRI or a CT scan, before their biopsy. The test results are used during the biopsy to select the areas of the prostate to sample.
Before your biopsy, you may be given antibiotics to prevent infection. You may be asked to take off all of your clothes and put on a hospital gown.
Through the rectum
- You may be asked to kneel, lie on your side, or lie on your back.
- Your doctor may inject an anesthetic around and into the prostate to numb the area before samples are taken.
- An ultrasound probe will be gently inserted into your rectum.
- A thin tool with a spring-loaded needle will be inserted next to the ultrasound probe. The ultrasound helps to locate the areas on the prostate where the samples will be taken. If you had an MRI or CT scan, the test results will also be used to guide the sampling.
- The needle enters the prostate and removes a sample. About 10 to 12 samples are usually taken.
Through the perineum
- You will lie on an exam table either on your side or on your back with your knees bent. You will get anesthesia. The anesthesia may make you sleep. Or it may just numb the area being worked on.
- Your doctor will make a small cut in your perineum. Then the doctor will collect samples from the prostate through the cut with a special tool.
- An ultrasound probe inserted into the rectum may be used to help find the locations in the prostate where samples need to be taken. Sometimes other imaging, such as MRI, is used instead of or along with ultrasound. Or the test results from other imaging, such as an MRI or a CT scan, may be used to guide the sampling.
- If you have a general anesthetic, you will be in a recovery room for a few hours after the biopsy.
How long the test takes
This test will take from 15 to 45 minutes, depending on how it's done.
How It Feels
With general anesthesia, you won't feel anything during this procedure. With local anesthesia, you may have some discomfort while numbing medicines are being injected and feel pressure in the rectum while the ultrasound probe is in place. And with local anesthesia, you may still feel some pressure or discomfort as the biopsy needle removes samples from the prostate. Usually about 10 to 12 samples are collected.
A prostate biopsy rarely causes problems with erections. It doesn't affect your fertility.
A prostate biopsy has a risk of causing problems such as:
- Infection. A urinary tract infection is the most common infection that can happen after a prostate biopsy. Less common infections include prostatitis, bacteremia, and sepsis. You will likely be given an antibiotic before the test to lower your chance for getting an infection.
- Urinary blockage. You may be unable to urinate after the biopsy if the swelling in your prostate blocks the flow. Or, in rare cases, the urine flow may be blocked by a blood clot caused by bleeding into the urinary tract.
Results are usually ready within several days.
The tissue samples look normal under the microscope. There are no signs of infection or cancer.
Cancer cells or signs of infection are found.
There are signs of an abnormal noncancerous enlargement of the prostate (benign prostatic hyperplasia, or BPH).
Normal prostate biopsy results do not rule out cancer. There's a chance that a cancer may be missed since the biopsy takes a small amount of tissue.
If the test finds prostate cancer cells, your biopsy report will include a Gleason score and a Grade Group number. These numbers are ways of describing how the cancer cells look under a microscope and how likely those cells are to grow quickly and spread. Your doctor will discuss this with you.
Current as of: May 4, 2022
Author: Healthwise Staff
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Christopher G. Wood MD, FACS - Urology, Oncology