The serum PSA level divided by the volume of the prostate can be useful to indicate whether a change in PSA is significant.
PSA density in ng/mL/cc =
= (PSA in ng/mL) / (prostate volume in cc from transrectal ultrasound)
Interpretation:
• A very low PSA density supports a benign diagnosis.
• An increase in PSA density warrants further investigation for carcinoma.
An alternative way to calculate PSA density (Bastian et al) is:
PSA density =
= (absolute PSA value in ng/mL) / (weight of prostatectomy specimen in grams after removal of the seminal vesicles)
where:
• The specific gravity of the prostate is approximately 1.050 (Watanabe et al), which means a weight in grams approximates the volume in cc.
Limitations:
• PSA density may be increased in prostatitis.
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Purpose: To interpret a patient's PSA results using the PSA density.
Specialty: Urology, Clinical Laboratory
Objective: laboratory tests
ICD-10: N40, N41, C61,
