## PSA Elevation: Specificity and Limitations **Key Point:** PSA is organ-specific (produced by prostate epithelium) but NOT cancer-specific. It is elevated in benign prostatic conditions and after mechanical trauma to the prostate. ### Causes of PSA Elevation **High-Yield:** PSA rises in three main clinical scenarios: 1. **Benign Prostatic Hyperplasia (BPH)** — enlarged prostate tissue produces more PSA 2. **Prostatitis** — inflammation or infection causes epithelial damage and PSA leakage into bloodstream 3. **Urinary Tract Instrumentation** — cystoscopy, catheterization, or digital rectal examination (DRE) causes mechanical trauma and transient PSA elevation ### Clinical Implications for PSA Testing **Clinical Pearl:** PSA should not be measured within 48 hours of DRE, cystoscopy, or ejaculation, as these cause false elevation. A single elevated PSA requires confirmation and clinical correlation. ### PSA Interpretation Framework | Condition | PSA Elevation | Mechanism | | --- | --- | --- | | Prostate cancer | Yes (often marked) | Malignant epithelial proliferation | | BPH | Yes (mild–moderate) | Increased glandular tissue mass | | Prostatitis | Yes (acute elevation) | Epithelial inflammation and leakage | | Urinary instrumentation | Yes (transient) | Mechanical trauma to epithelium | | UTI (without instrumentation) | No/minimal | Infection distal to prostate | **Mnemonic:** **PSA = Prostate-Specific, not cancer-specific** — remember BPI (BPH, Prostatitis, Instrumentation) as non-malignant causes. **Warning:** Do NOT diagnose prostate cancer on PSA alone. Elevated PSA requires biopsy confirmation and clinical context (age, DRE findings, PSA velocity, free PSA %). [cite:Harrison 21e Ch 297] 
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