A case of high-grade prostate cancer with low PSA levels.

Prostate-specific antigen (PSA) levels typically correlate with the risk of prostate cancer. However, it is uncommon for an extensive malignant infiltration to occur with persistently low PSA levels. We present a case of a young male with a large tumor originating from the transition zone of the prostate and with low PSA levels This case underscores the biological heterogeneity of prostate cancer and suggests that tumors arising in the transition zone may differ significantly in behavior from those originating in the peripheral zone.