(I) Diagnostic principles
It is recommended to diagnose prostatitis according to NIH staging.
Type I: The diagnosis mainly relies on history, physical examination and bacterial culture results of blood and urine. Rectal examination of the patient is necessary, but prostate massage is contraindicated. Before applying antibiotic treatment, a midstream urine culture or blood culture should be performed. After 36 hours of standardized treatment, if the patient’s condition does not improve, transrectal ultrasound and other examinations are recommended to fully evaluate the lower urinary tract lesions and to clarify the presence of prostatic abscesses. Successful urology department of the First Affiliated Hospital of Nanjing Medical University
The “two-cup method” or “four-cup method” is recommended for pathogen localization testing.
For diagnosis and differential diagnosis, the following tests are available: semen analysis or bacterial culture, prostate-specific antigen (PSA), urine cytology, transabdominal or transrectal ultrasound (including residual urine measurement), urine flow rate, urodynamics, CT, MRI, urethral cystoscopy, and prostate puncture biopsy.
Type IV: asymptomatic, detected during prostate massage fluid (EPS), semen, urine after prostate massage, prostate tissue biopsy and pathological examination of prostatectomy specimens.
(B) Diagnostic methods
Specific diagnostic methods for prostatitis include.
1, clinical symptoms
When diagnosing prostatitis, a detailed history should be taken to understand the cause or trigger of the onset; ask about the nature, characteristics, location, degree of pain and abnormal urination and other symptoms; understand the treatment and recurrence; evaluate the impact of the disease on the quality of life; and understand the past history, personal history and sexual life.
Type I: Often sudden onset, manifested by general symptoms such as chills, fever, fatigue and weakness, accompanied by pain in the perineum and suprapubic area, urinary tract irritation and difficulty in urination, and even acute urinary retention.
Types II and III: The clinical symptoms are similar, mostly with pain and abnormal urination. Type II may manifest as recurrent lower urinary tract infections. Type III mainly manifests as pain in the pelvic region, which can be seen in the perineum, penis, perianal area, urethra, pubic bone or lumbosacral area. Urinary abnormalities can be manifested as urinary urgency, frequency, painful urination and increased nocturia. As chronic pain remains untreated for a long time, the patient’s quality of life decreases and may have sexual dysfunction, anxiety, depression, insomnia and memory loss.
Type IV: No clinical symptoms.
2.Physical examination
To diagnose prostatitis, a comprehensive physical examination should be performed, focusing on the genitourinary system. Check the patient’s lower abdomen, lumbosacral region, perineum, penis, urethral orifice, testes, epididymis and spermatic cord for any abnormalities, which helps in making diagnosis and differential diagnosis. Rectal finger examination is very important for the diagnosis of prostatitis and helps to identify perineal, rectal, neuropathy or other diseases of the prostate, as well as obtaining EPS by prostate massage.
Type I: Physical examination may reveal suprapubic pressure and discomfort, and in those with urinary retention, a suprapubic bulging bladder may be palpated. Rectal finger examination may reveal enlarged prostate, tenderness, elevated local temperature and irregular shape. Prostate massage is contraindicated.
The prostate gland may be found to be enlarged, painful to palpate, with or without nodules, and with or without pressure and pain in the pelvic floor muscles.
3.Laboratory tests
(1) EPS routine examination: EPS routine examination is usually performed by wet smear method and microscopic examination by hematocrit plate method, the latter having better accuracy.
A normal EPS with 10 leukocytes/HP and a reduced number of leukocyte vesicles has diagnostic significance. The number of leukocytes does not correlate with the severity of symptoms. Macrophages containing components such as phagocytosed lecithin vesicles or cellular debris in the cytoplasm are also characteristic of prostatitis. When the prostate is infected with pathogens such as bacteria, fungi and trichomonas, these pathogens can be detected in the EPS.
In addition, in order to clearly distinguish between components such as leukocytes in EPS, the EPS can be identified using methods such as Gram staining.
If EPS cannot be collected after prostate massage, it is not advisable to repeat the massage several times, and the patient can be allowed to retain the urine after prostate massage for analysis.
(2) Routine urine analysis and urine sediment examination: Routine urine analysis and urine sediment examination are auxiliary methods to exclude urinary tract infection and diagnose prostatitis.
(3) Bacteriological examination.
1) Type I: Stain microscopy, bacterial culture and drug sensitivity test of the middle urine, and blood culture and drug sensitivity test should be performed.
2) Chronic prostatitis (type II and III): the “two-cup” or “four-cup” pathogen localization test is recommended.
A “four-cup method”: In 1968, Meares and Stamey proposed the use of sequential collection of the patient’s segmental urine and EPS for separate culture (referred to as the “four-cup method”) to differentiate between male urethral, bladder and prostate infections.
(4) Other laboratory tests: Patients with prostatitis may have abnormalities in semen quality, such as increased leukocytes, non-liquefaction of semen, hematospermia and decreased sperm quality. Elevated PSA may also be seen in some patients with chronic prostatitis. Urine cytology has some value in differentiating from carcinoma in situ of the bladder, etc.
(iii) Differential diagnosis
Type III prostatitis lacks an objective and specific diagnostic basis. The clinical diagnosis should be differentiated from diseases that may cause pain in the pelvic region and abnormal urination. Patients with predominantly abnormal urination should be clearly identified with or without bladder outlet obstruction and abnormal bladder function. Diseases to be differentiated include: benign prostatic hyperplasia, testicular epididymal and spermatic cord disease, overactive bladder, neurogenic bladder, interstitial cystitis, adenocystitis, sexually transmitted diseases, bladder tumors, prostate cancer, anorectal disease, lumbar spine disease, central and peripheral neuropathy, etc.
Patients with type III prostatitis whose symptoms are not relieved after treatment should be selected for further tests, depending on the specific case, to exclude the above-mentioned diseases.