Immunohistochemical study of prostate-specific antigen in normal and pathological human tissues: Special reference to the male and female prostate and breast

Immunohistochemical methods were used to study the expression of prostate-s pecific antigen (PSA) in more than 400 samples of normal and pathological h uman tissues, including the female and male breast, male and female prostat e (Skene's gland), and selected other tissues. In the normal female and mal e breast, no immunohistochemical positivity of PSA was observed in epitheli al structures. In contradistinction to normal breast, normal male and femal e prostate tissue exhibited regular and marked PSA positivity. Variable exp ression of PSA was observed in membranes of adipocytes in breast tissue and axilla, apocrine sweat glands, endothelium of small vessels, gastric parie tal cells, and some further rare normal extraprostatic tissue components. U nlike normal breast tissue, apocrine metaplasia in benign female breast dis ease and in male gynecomastia displayed distinct positivity for PSA. In can cerous female breast, expression of PSA decreased with the decreasing degre e of differentiation. High expression was recorded in the signet-ring cell variant of ductal female breast carcinoma. If we disregard the absence of e xpression of PSA in the normal breast and its minimal and variable PSA expr ession of some normal extraprostatic structures, it is evident that in the female, similarly as in the male, the prostate is the principal source of P SA. In cases of discussed pathological breast tissues and other pathologica l tissues known to produce PSA, the total amount of PSA is the summation of normal prostatic and anomalous extraprostatic pathological tissue producti on in the male and female patient.