Malakoplakia of the Prostate as a Mimicker of Prostate Cancer on Prostate Health Index and Magnetic Resonance Imaging-Fusion Prostate Biopsy: A Case Report.

Background: Isolated malakoplakia of the prostate is a rare inflammatory condition that has been clinically mistaken for prostatic malignancies. The development of Prostate Imaging Reporting and Data System (PI-RADS) classifications, and Prostate Health Index (PHI) has led to more accurate diagnosis of clinically significant disease and stratification of patients that may be at risk of prostate cancer. Case Presentation: We present a case of a 75-year-old male who was on follow-up with our hospital for elevated prostate specific antigen (PSA). He was admitted for an episode of urosepsis, which was treated with antibiotics and subsequently underwent further workup and was found to have a raised PHI, as well as a high PI-RADS classification and was later found to have malakoplakia based on histology of prostate tissue obtained during targeted magnetic resonance imaging (MRI)-guided fusion prostate biopsy. Conclusion: To our understanding, this is the first case where a prostate lesion has been labeled as a PI-RADS 5 lesion, with elevated PHI that has subsequently been proven histologically to be malakoplakia. An important possible confounder is the interval between the MRI and the episode of urosepsis and it is well known that urosepsis can affect the PSA and MRI result. We present this case to highlight the potential for a false diagnosis of prostate cancer, in spite of laboratory and radiological findings.