Immunohistochemical expression of embryonal marker TRA-1-60 in carcinoma in situ and germ cell tumors of the testis.

BACKGROUND

Testicular cancer is preceded by the noninvasive stage of carcinoma in situ (CIS). According to a recent hypothesis, testicular CIA cells are germ cells transformed in fetal life. The idea of an embryonal origin of testicular germ cell neoplasia would be strengthened by the finding of antigenic similarity between fetal germ cells, CIS cells, and invasive testicular germ cell tumors.

METHODS

Monoclonal antibody (MoAb) TRA-1-60 raised against a human embryonal carcinoma cell line was immunohistochemically tested on 21 fetal gonads (11 male gonads and 10 female gonads; 11th-24th week of gestation). In addition, TRA-1-60 was tested on tissue from 27 testes with CIS, 11 testes with invasive testicular cancer, and 24 adult and 4 infant testicular control specimens.

RESULTS

Expression of TRA-1-60 was found in germ cells of six female and two male fetal gonads. In addition, 26 of 27 adult human testes with CIS, 7 of 8 seminomas, and 3 of 3 embryonal carcinomas were TRA-1-60 positive.

CONCLUSIONS

The study demonstrated an antigenic link between fetal germ cells, cells of CIS and seminomas, and embryonal carcinomas. The results provided additional evidence for the hypothesis that testicular neoplasia arises during early fetal life and CIS cells are malignant fetal gonocytes.