Acute Bacterial Prostatitis Workup

Updated: Jul 20, 2022
  • Author: Samuel G Deem, DO; Chief Editor: Edward David Kim, MD, FACS  more...
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Approach Considerations

The diagnosis of acute bacterial prostatitis (ABP) can be made on the basis of clinical findings and urine studies. Although prostatic secretions in patients with acute bacterial prostatitis contain large numbers of leukocytes and fat-laden macrophages, prostatic massage to obtain secretions should not be performed as it is rarely necessary for diagnosis.

Prostatitis may cause irritative and obstructive voiding symptoms that mimic other primary causes of those symptoms, and in such cases the use of urodynamics may possibly be helpful to avoid misdiagnosis. However, this is more the situation in chronic prostatitis; in acute prostatitis, this should not be necessary.

Acute bacterial prostatitis may be an incidental finding on a cross-sectional prostate imaging study. [13] However, imaging studies are not  needed in uncomplicated cases. The presence of a prostatic abscess is confirmed with transrectal ultrasonography and noncontrast computed tomography (CT) scanning of the pelvis.

Occasionally, blood culture results are positive.


Urine Studies

A urinalysis that shows leukocytes and a positive result on urine culture are essential for the diagnosis of acute bacterial prostatitis (ABP). To confirm the prostate as the site of involvement, the tests can be conducted on paired urine specimens collected before and after massage of the prostate; this is known as the two-glass test. [14]

If the patient is febrile or exhibits signs of acute bacterial prostatitis, only the midstream urine is collected for urine culture. The prostatic massage is contraindicated.

Urethral swab culture and postmassage urine culture as well as microscopic examination may be an alternative standard protocol to simplify the evaluation of prostatitis-like syndrome in clinical practice. [15]

The evaluation for chronic prostatitis may include first-voided urine, midstream urine, urine after prostatic massage, and expressed prostatic secretions to localize the nidus of infection, as described by Meares and Stamey. [16]


Serum PSA Levels

Serum prostate-specific antigen (PSA) levels are also increased in prostatitis but should not be used as a screening test for this condition. In the setting of acute bacterial prostatitis, PSA has little to no clinical value. If the PSA level is obtained and is found to be elevated, the study should be repeated 30-60 days after adequate treatment. Studies have shown that a 2- to 4-week treatment with antibiotics decreased the PSA levels in approximately half of patients with PSA levels in ray zone who did not have prostatitis symptoms. [17]


CT Scanning/Transrectal Ultrasonography

Imaging studies, including computed tomography (CT) scanning of the pelvis or transrectal ultrasonography, should be reserved for cases in which findings from laboratory analyses are equivocal or when no improvement is observed following medical therapy.

Ruling out complications of prostatitis (eg, prostatic abscess) is a strong indication to proceed to imaging studies. Transrectal ultrasonography and CT scanning of the pelvis can be very useful in diagnosing and draining prostatic abscesses. [18] However, transrectal ultrasonography should be performed as gently as possible to prevent bacteremia.



Biopsy and Histology

Histologically, the normal prostate gland is composed of tubuloalveolar glands. The glandular spaces are lined by epithelium, which is composed of 2 layers of cells—a basal layer of low cuboidal epithelium covered by a layer of columnar mucus-secreting cells. The glands have a distinct basement membrane and are separated by a fibromuscular stroma.

Prostate biopsy is contraindicated in patients with suspected acute bacterial prostatitis because of the potential complication of seeding the bacterial infection in adjacent organs and the risk of gram-negative sepsis. Furthermore, prostate biopsy is extremely painful without a prostatic nerve block. The current practice is to anesthetize the area before core biopsy sampling.

In prostatitis, a stromal leukocytic infiltrate may be accompanied by increased prostatic secretion or leukocytic infiltration within gland spaces (see image below). When complicated by abscess formation, focal or larger areas of the prostate become necrotic.

Leukocytic infiltration of the stroma and glandula Leukocytic infiltration of the stroma and glandular lumina during acute bacterial prostatitis (ABP).