KLK3 and Familial prostate cancer: Biopsy-confirmed metastatic lesions in the bladder, rectum, and bone were observed with a pathologic diagnosis of prostate cancer with small cell features, which was supported by negative PSA, positive synaptophysin (SYP) and positive chromogranin (CHGA) on biopsy tissue immunohistochemistry (IHC) (Fig. 3D).