The prostate gland is a small gland in the male reproductive system that secretes a fluid that combines with sperm to form semen. The gland sits right below the bladder and surrounds parts of the urethra, which is the tube that carries urine out of the body. As men age, the prostate may grow bigger and cause a condition called benign prostatic hyperplasia (BPH), which is non-cancerous but can be uncomfortable. BPH doesn’t increase a man’s chances of having prostate cancer, but if it goes untreated, the symptoms can become worse and lead to more serious problems like urinary tract infections, bladder or kidney damage, or incontinence.
Normally, the prostate is about the size of a walnut. However, as men get older and the condition known as BPH develops, the prostate grows larger and can be up to 3 times its normal size, weighing more than 80 grams. This is one of the leading reasons why men experience LUTS symptoms, such as painful and difficult urination.
Although the exact cause of BPH is not clear, experts believe certain male hormones play a role. This includes dihydrotestosterone, which is produced by the testicles. This testosterone derivative is known to increase the size of the prostate and, as men get older, they can experience enlargement.
Most cases of enlarged prostate are caused by BPH, but it can also be due to some medications and other conditions. A patient’s history, symptoms, and physical exam can help diagnose the condition. Some of the most common tests include a digital rectal exam and blood work. A urologist can also perform a cystoscopy, a procedure in which they pass a tiny camera into the urethra, to see if there is any prostate tissue that has a lot of inflammation and could be causing symptoms.
In addition to traditional imaging, elastography of the prostate can provide a more accurate measurement of its volume by comparing stiffness between different regions. This technique requires the prostate to be compressed manually, which can lead to false-positive findings, especially if the compression is not consistent. In the future, new techniques for prostate elastography should allow for more standardized compression and reduce false-positive results.
The prostate can also be evaluated with ultrasound. There are several methods for estimating its size, but the most popular is using a one-dimensional formula that multiplies the largest transverse and longitudinal prostate diameters by 0.524 (H x W x L). This formula is fast and easy to use and correlates well with the actual volume of the gland. Other techniques for assessing prostate volume include step-section planimetry, rotational body measurements, and the prolate ellipsoid method.
