Specialties: Anatomic Pathology Genitourinary (GU) Pathology

Prostate-Specific Antigen (PSA) is a 33 kDa protein primarily produced by the prostatic epithelium and the epithelial lining of the periurethral glands ¹. PSA is strongly expressed in both normal and neoplastic prostatic tissue. Although PSA can be considered prostate-specific, PSA and/or PSA gene expression has been detected at low levels in some extra-prostatic tissues such as normal breast tissue, breast tumors, endometrium, adrenal neoplasms and renal cell carcinomas ^{1, 2, 3}. Anti-PSA is most useful in determining the prostatic origin of carcinomas in non-prostate tissues (metastatic disease) using IHC techniques.   This product is best used in conjunction with a panel of antibodies as, up to 27% of prostate carcinoma cases (predominantly poorly differentiated carcinomas) can be negative for this marker.⁴