Prostein

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.

Prostein is selectively expressed in both benign and malignant prostatic tissues, and is a highly sensitive and specific immunohistochemical marker for identifying prostate tissue. It is a useful marker for metastatic adenocarcinoma of unknown primary when prostatic carcinoma is suspected. It is also helpful to include prostein in a panel of antibodies (PSA, NKX3.1, PSAP, GATA3, HMWK, and p63) in the differential diagnosis of high-grade prostatic adenocarcinoma versus urothelial carcinoma when encountering a poorly differentiated carcinoma, such as in a TUR specimen.