Prostate Biopsy Health Article

Definition

Prostate biopsy is a surgical procedure to remove small samples of prostate tissue for microscopic examination. The prostate gland lies just below the urinary bladder and surrounds the urethra. The gland produces enzyme-rich secretions that contribute to the seminal fluid via ducts that enter the urethra.

Purpose

A prostate biopsy is usually performed to determine whether the patient has prostate cancer. Occasionally, it may also be used to diagnose a condition called benign prostatic hypertrophy (BPH), a progressive enlargement of the prostate that may cause obstruction of urine flow in older males.

A prostate biopsy is ordered when other tests have indicated a need to visualize samples of prostate tissue for abnormalities. These tests are the digital rectal examination (DRE) and the prostate-specific antigen (PSA) blood test. The DRE is a routine screening test performed by the physician to feel for any enlargement or nodular growth of the patient's prostate. Higher than normal levels of the protein marker PSA can be an indicator of prostate cancer. If either the DRE or PSA results are abnormal, the physician may order additional tests, including a prostate biopsy. Computed tomography scans, magnetic resonance imaging, and ultrasonograms provide detailed pictures of the prostate and can also be used to determine the extent and spread of prostate disease. However, a prostate biopsy (examination of the cells of the gland under a microscope) remains the most definitive test for diagnosing and staging prostate cancer.

Precautions

A prostate biopsy is ordered only when the physician has used prior diagnostic tools that indicate an abnormal prostate. Prostate biopsies are usually performed by a urogenital system specialist (urologist). Special precautions will be required before the biopsy if the patient has a history of abnormal bleeding or is currently taking a blood-thinning medication.

Description

According to the American Cancer Society, next to skin cancer, prostate cancer continues to be the most commonly diagnosed cancer in American men. Prostate biopsies are usually performed in one of two ways. They can be performed by inserting a needle through the wall of the rectum or by inserting a needle through the perineum (the area between the base of the penis and the rectum). The patient may be given a sedative to help him relax. In preparation for the biopsy the patient will have an enema, and will begin antibiotic therapy to prevent an infection.

Needle biopsy via the rectum

This procedure, called a transrectal ultrasound-guided biopsy, is the most commonly performed type of prostate biopsy, and can usually be performed in the physician's office without general anesthesia. The patient is asked to lie on his side or on his back with his legs in stirrups. Local anesthetic is administered, and the urologist uses a thin needle attached to a spring-loaded gun directed by ultrasound to collect samples from the prostate. The gun is able to insert and remove the needle into the prostate tissue rapidly, creating less discomfort and trauma for the patient. The procedure can often be completed within 30 minutes. Usually the tissue samples are obtained by fine-needle aspiration, as opposed to larger core tissue samples that create more discomfort for the patient.

Needle biopsy via the perineum

If the chances of a complication for the patient are too great for the transrectal ultrasound-guided biopsy, the urologist may choose another route through the perineum for access to the prostate. The skin of the perineum is thoroughly cleansed and a local anesthetic is injected at the site where the biopsy is to be performed. Once the area is numb, the physician makes a small (1 in/2.5 cm) incision in the perineum. The physician places one finger in the rectum to guide the placement of the biopsy needle, and the needle is then inserted into the prostate. A small amount of tissue is collected and the needle is withdrawn. The needle is then reinserted into another part of the prostate and another sample of tissue is collected. In this manner, samples are collected from several areas. After the procedure, pressure is applied at the biopsy site to stop bleeding. The patient usually experiences only slight discomfort and the procedure can often be completed within 30 minutes.

Preparation

Before scheduling the biopsy, the physician, nurse, or physician assistant completes a thorough medical history of the patient to include all medications that the patient is taking; a list of any medications to which the patient is allergic; and a history of any bleeding problems. The patient may be given an antibiotic shortly before the test to reduce the risk of infection. Usually an enema is required prior to the biopsy procedure, and the patient will be given instructions on administering the enema.