BACKGROUND: Prostate cancer (PCa) is the most common malignancy in men. The multiparametric MRI (mpMRI) significantly improved the diagnostic approach of PCa. Although PCa is highly likely to be present in prostate imaging-reporting and data system (PI-RADS) 5 lesions, there are up to 18% of PI-RADS 5 lesions with benign histopathology after targeted biopsy.
METHODS: We present the case of a 66-year-old man who was referred to our hospital for MRI/ultrasound fusion-based targeted biopsy due to an elevated PSA and a PI-RADS 5 lesion described in the mpMRI. After 2 consecutive biopsies, the mpMRI target showed no malignancy. The lesion was described as PI-RADS 2 two years later.
CONCLUSIONS: This case demonstrates the risk of false-positive classified PI-RADS 5 lesions in the mpMRI and the challenge in some cases to distinguish between BPH nodules and cancer. Until today, a limited amount of studies exists concerning this issue. However, further studies are required to evaluate further characteristics associated with a higher possibility of histopathologically benign findings in PI-RADS 5 lesions.

OBJECTIVE: To evaluate if MRI/ultrasound fusion based targeted biopsy (FBx) leads to a reduced rate of change in Gleason score (GS) compared to prostatectomy specimen.
METHODS: The histopathological findings of the biopsy of the prostate and the radical prostatectomy (RP) specimen of 210 patients who were referred to our hospital between 2012 and 2017 were compared retrospectively in this study. One hundred and five patients who underwent FBx combined with ultrasound-guided 12-core biopsy of the prostate (SBx) were matched with 105 patients who underwent SBx only. This study evaluated the rate of up- or downgrading in the RP specimen in both groups and compared the results via matched pair analysis.
RESULTS: Concordance in Gleason grade group (GGG) was found in 52/105 patients (49.5%) in SBx and in 49/105 patients (46.7%) with FBx (p = 0.679). The rate of downgrading was statistically significant (p = 0.014) and was higher in the FBx group (14/105 patients, 13.3%) than in the SBx group (4/105 patients, 3.8%). A higher rate of upgrading was seen in SBx (49/105 patients; 46.7%) compared to FBx (42/105 patients; 40%), with no statistical significance (p = 0.331). The change in GGG from biopsy to final pathology in patients with GGG 1 and 2 at biopsy level was not statistically significant (p = 0.168).
CONCLUSIONS: FBx does not decrease the rate of upgrading between biopsy and final pathology in RP specimens. Our results indicate that FBx tends to overestimate the final GGG compared to SBx.