PSA

Formalin-fixed, paraffin embedded tissue block or cell block, or 1 unstained charged slide for each test requested plus 3-4 additional unstained slides cut at 4 microns. Adequate space on each slide for control tissue is required.

PSA is a sensitive and specific marker for prostate tissue. It is expressed in greater than 95% of prostatic adenocarcinoma, and may be used in the setting of adenocarcinoma of unknown primary. PSA expression may rarely be seen in a minority of nonprostatic tumors, such as breast and salivary gland cancers.