Prostatic Inflammation

Prostatic inflammation is defined and analyzed in three different aspects: pathological, clinical, and imaging. The relationship among clinical features due to infection or prostatitis-like symptoms is not strictly correlated with imaging and pathology. From a pathological point of view, prostatic inflammation (PI) implies the presence of pathological infiltration of the prostate by inflammatory cells. Pathological classification of prostatic inflammations has been graded according to extent, type of inflammatory cells (lymphocytes, neutrophils, etc.), and relationship with stroma and epithelium. Acute or chronic PI is found frequently in needle biopsy specimens. There are conflicting data on the relationship of acute or chronic inflammation on needle biopsy with serum PSA and clinical symptoms of prostatitis. Therefore, pathologists use the term prostatic inflammation, which differs from prostatitis that describes a clinical condition (Montironi et al., Virchows Arch 449:1–13, 2006). From a clinical point of view, prostatic inflammation is a clinical condition defined as prostatitis. That means inflammation of the prostate gland with acute or chronic symptoms that may be associated to infection. Prostatitis has a wide range and severity of clinical signs and symptoms. A recognized definition includes “a combination of acute and chronic infectious diseases (bacterial prostatitis), chronic pelvic pain syndrome (CPPS) and asymptomatic inflammations” (Krieger et al., JAMA 282:236, 1999). Prostatitis is a heterogeneous clinical entity, and current clinical and pathological classification is reported with ultrasound correlations. Prevalence in population is estimated to be 12% (Krieger et al., Int J Antimicrob Agents 31:S85–S90, 2008). The role of imaging in prostatitis is usually to rule out other differential diagnoses of lower urinary tract symptoms (bladder cancer, urinary stones, etc.) and to assess for complications of acute prostatitis (abscess). Ultrasound is not specific for prostatitis, but it is recommended as first-line imaging to differentiate prostatitis from prostate cancer. Also, the relationship of acute or chronic inflammation with imaging is conflicting, as well for pathology report, particularly in men with elevated serum PSA or clinical symptoms of prostatitis. Therefore, the imaging report should use the term prostatic inflammation rather than prostatitis, which describes a clinical condition. We reviewed ultrasound features of prostatic inflammation including fluid collection within the prostate requiring ultrasound-guided drainage.