Which patients are at risk for developing a prostatic abscess, and what are its cross sectional imaging features?
Prostatic abscesses are encountered in up to 2.5% of patients who are hospitalized for prostatitis and are secondary to Gram negative organisms in 90% to 95% of cases, most often Escherichia coli . Risk factors include diabetes mellitus, chronic dialysis, immunosuppression, chronic urinary catheterization, and recent urethral manipulation. Treatment is typically with antimicrobial drugs and percutaneous or transurethral drainage.
On cross-sectional imaging, a prostatic abscess appears as a heterogeneous multiloculated complex cystic lesion with complex fluid, internal septations, thick rim enhancement on CT and MRI, and peripherally increased blood flow on Doppler US. Ill-defined focal enlargement of the prostate gland may be seen prior to liquefaction into an abscess. The presence of internal gas is highly specific for this diagnosis. Additional findings of coexistent acute prostatitis and seminal vesiculitis may also be seen