Negative Biopsy Histology in Men With PI-RADS Score 5 in Daily Clinical Practice: Incidence of Granulomatous Prostatitis

IntroductionThe purpose of this study was to evaluate the biopsy histology of men who underwent transperineal multi-parametric magnetic resonance imaging (mpMRI)/transrectal ultrasound fusion biopsy for Prostate Imaging Reporting and Data System (PI-RADS) score 5 lesions.Patients and MethodsFrom January 2016 to June 2019, 105 men with PI-RADS score 5 underwent mpMRI/transrectal ultrasound fusion biopsy combined with systematic prostate biopsy. All the patients underwent a 3.0 Tesla pelvic mpMRI for the first time before prostate biopsy. In detail, the detection rate for clinically significant prostate cancer (PCa) and the follow-up of the patients without proven diagnosis of PCa has been reported.ResultsIn 91 (86.7%) of 105 patients, a stage T1c PCa was diagnosed, and 89 (84.5%) of 105 of them were classified as clinically significant PCa. Among the 16 (15.5%) of 105 patients with absence of cancer, 5 (31.5%) of 16 had an aspecific granulomatous prostatitis, 1 (6.2%) of 16 had a specific granulomatous prostatitis secondary to prostatic Mycobacterium Tubercolosis, and 10 (62.3%) of 16 had a diagnosis of normal parenchyma. The 6 patients with granulomatous prostatitis underwent specific antibiotic therapy followed by laboratory (ie, semen and urine cultures) and clinical evaluation. Six months from prostate biopsy, none of the 16 patients underwent repeat prostate biopsy because prostate-specific antigen (PSA) (15/16 cases) plus PSA density significantly decreased; in addition, in all the cases the initial PI-RADS score 5 was downgraded at mpMRI revaluation to PI-RADS score ≤ 3.ConclusionThe reduction of PSA plus PSA density values and the downgrading of PI-RADS score to ≤ 3 allow avoiding a repeated prostate biopsy in men with initial mpMRI PI-RADS score 5 lesion and negative biopsy histology.