Endometrioid carcinoma of the prostate. The diagnostic value of Leu7 and prostatic specific antigen.

In a case of endometrioid carcinoma of the prostate the expression of Leu7 and prostatic specific antigen (PSA) was studied immunohistochemically on paraffin sections. The same markers were studied in 14 cases of prostatic cancer and 14 cases of uterine endometrial carcinoma. Endometrioid carcinoma of the prostate was negative for Leu7 and PSA, while all prostatic cancer specimens were positive for the above markers. All uterine endometrial carcinomas were negative for PSA and only a small percentage of cells in 4 specimens were positive for Leu7. The absence of Leu7 and PSA in this case of endometrioid carcinoma strongly suggests a müllerian origin.