Methods for collecting prostatic fluid, analysis of normal and pathological states, and clinical significance of testing.

The prostate is an important accessory gland that secretes prostatic fluid. Changes in the biochemical composition of prostatic fluid can reflect the physiological function of the prostate. To accurately determine pathological changes in the prostate, prostatic fluid examination is necessary. Routine prostatic fluid examination is a standard examination procedure in male urological diseases.

In hospitals, prostate fluid is typically collected using the four-glass method. First, 10ml of urine is collected, representing the urethral specimen. Then, 200ml of urine is urinated and discarded, followed by another 10ml of midstream urine. Next, the prostate is massaged and squeezed through the rectum, and prostate fluid is collected from the urethral opening. After the massage, another 10ml of urine is collected, representing the condition of the prostate and posterior urethra. These four specimens are then subjected to microscopic examination, cell counting, culture, and antibiotic sensitivity testing. This process aids in the localization and diagnosis of lesions.

Prostatic fluid is a milky white, semi-transparent, thin liquid and a component of semen. Routine examination of prostatic fluid generally refers to its appearance and microscopic examination. Microscopic examination of prostatic fluid mainly includes the number of white blood cells, red blood cells, lecithin bodies, trichomonas, sperm, tumor cells (requiring staining), amyloid bodies, and the presence of bacteria. Normal prostatic fluid shows a large number of evenly distributed lecithin bodies under a microscope, 0-2 white blood cells per high-power field, a small number of epithelial cells from the prostate and urethra, and sometimes amyloid bodies, which are more common in older men; sperm is occasionally seen.

In mild prostatitis, the appearance of prostatic fluid is not significantly changed. In more severe cases, it may be purulent or bloody to varying degrees. The prostatic fluid is thick, yellow, cloudy, or contains flocculent material. In prostate cancer, the prostatic fluid is often bloody to varying degrees. In mild prostatitis, microscopic examination reveals an increased number of white blood cells, often exceeding 10 per high-power field, which may appear in clumps; increased epithelial cells and decreased lecithin bodies. In more severe cases, microscopic examination reveals a large number of white blood cells and epithelial cells, as well as varying numbers of red blood cells; lecithin bodies are significantly reduced. In seminal vesiculitis and prostate cancer, a large number of red blood cells are visible in the prostatic fluid; trichomonas is visible in trichomonal prostatitis.

Basic tests for prostatic fluid include: color examination, volume examination, lecithin body assay, amyloid body assay, cell examination, trichomonas examination, sperm analysis, bacterial analysis, and pH measurement. The specific significance of these tests is as follows.

(1) Color examination: Normally, it is a thin, milky white fluid. In cases of prostate disease (such as prostatitis or prostate cancer), red, sticky fluid or light yellow, purulent fluid may appear.

(2) Quantity examination: Normally, it is a few drops to 1 ml. The amount of excretion increases in prostatitis.

(3) Lecithin body assay: Normally, there are abundant lecithin bodies that are evenly distributed throughout the field of view. In prostatitis, lecithin bodies are often reduced or absent, and their distribution is uneven, tending to clump together.

(4) Amyloid body measurement: Rarely seen in normal individuals, but more common in the elderly. It is more common in the elderly and is generally considered to have no significant relationship with disease.

(5) Cell examination: White blood cells: <10/HP (high power field); Red blood cells: <5/HP; Epithelial cells: few; Granular cells: occasionally seen; Cancer cells: none. In prostatitis, white blood cells are increased, and clumps of white blood cells can be seen in the prostatic fluid; in prostate cancer, red blood cells are increased. Excessive massage can also result in more red blood cells; in prostate lesions, increased epithelial cells are seen; in prostatitis or in elderly individuals, increased granular cells in the prostate are seen; the presence of cancer cells in prostatic fluid is of diagnostic value for prostate cancer.

(6) Trichomonas examination: Normally, it should not be detected. If trichomonas is found in the prostatic fluid, it can confirm the diagnosis of trichomonal prostatitis.

(7) Sperm examination: The presence of sperm in prostatic fluid is not related to disease. Sperm may appear in prostatic fluid because the seminal vesicles are massaged and compressed when prostatic fluid is collected.

(8) Bacterial examination: In cases of prostatic abscess, the secretions are thick and often contain mucus, and bacteria can be found. Common pathogens include Escherichia coli, Staphylococcus, and Streptococcus.

(9) pH test: Under normal circumstances, prostatic fluid is slightly acidic, and some laboratories report it to be slightly alkaline, with a pH range of 6.7 to 7.3. The pH of prostatic fluid becomes more alkaline with age. When inflammation occurs, the pH can increase to 7.7 to 8.5.

(1) When collecting prostatic fluid: If the massage is too forceful, it will cause minor damage to the prostate wall, resulting in an increase in the number of red blood cells in the prostatic fluid.

(2) Congestion phase of prostatitis: The number of white blood cells in the prostatic fluid may be normal or decreased. This is due to congestion, edema or fibrosis of the prostatic ducts and interstitial tissue causing duct obstruction.

(3) Uneven prostate fluid smear: Incorrect operation technique can lead to errors in examination results.

(4) After masturbation, intercourse, or sexual arousal: the total white blood cell count in prostatic fluid may temporarily increase.

Chromosomes are the genetic material within cells. Normal adults have 46 chromosomes, including two sex chromosomes. Males have one X chromosome and one Y chromosome. Females have two X chromosomes. Chromosomes control our growth and development. Abnormalities in the number or structure of chromosomes can cause diseases called chromosomal disorders.