Ectopic Production of Prostate Specific Antigen (PSA) in Breast and Ovarian Cancer

 

Tumors associated with ectopic PSA production:

(1) breast cancer in a female or male

(2) ovarian cancer in a female

 

Ectopic production of PSA may be encountered as:

(1) presence of measurable serum PSA levels in a woman

(2) unexplained elevated serum PSA levels in a male

(3) metastatic tumor in a male with positive immunostaining for PSA (often weak and/or patchy)

 

In a patient with ectopic PSA produced by a tumor, rising levels may be a sign of tumor recurrence.

 

Differential diagnosis:

(1) antibody in the patient to an animal that is the source for antibodies used in the PSA assay

(2) prostate cancer (in a hermaphrodite or following sex change)

(3) specimen mixup