A challenging diagnosis of prostate cancer seeding in the perineal needle-tract after transperineal biopsy: is PET-CT the imaging of choice?

Perineal seeding is an extremely rare complication after prostate biopsy. We found a perineal localization of prostatic adenocarcinoma 5 years after the transperineal biopsy in a patient with metastatic castration resistant prostate cancer. The tumor was identified by a18F-Fluorocholin positron emission tomography-computed tomography (18F-FCH PET-CT) performed after a sudden rise of PSA levels during androgen deprivation therapy and after a negative CT scan. This case report underscores the challenge one may encounter in detecting perineal prostate cancer metastasis after a biopsy when using traditional imaging with CT scan alone or MRI, and the added diagnostic value of PET-CT imaging.