Loss of CD30 expression in metastatic embryonal carcinoma: the effects of chemotherapy?

Aims: CD30 has been shown to be consistently strongly expressed in embryona l carcinomas. Our aim was to examine changes in CD30 expression in embryona l carcinomas before and after treatment with chemotherapy. Methods and results: One hundred and eighteen retroperitoneal lymph node di ssections from patients with metastatic germ cell tumours were reviewed. Se venteen contained embryonal carcinoma deposits. In nine cases. the matching pre-chemotherapy orchidectomy specimens were available. The cases were imm unohistochemically stained for CD30. All nine pre-chemotherapy orchidectomy specimens showed embryonal carcinoma and stained strongly positively for C D30. However. only tour out of nine of the matched post-chemotherapy retrop eritoneal lymph node dissection specimens and a total of SIX Out of 17 (35% ) with embryonal carcinoma deposits stained for CD30. Ten seminomas were ne gative for CD30. Loss of CD30 did not appear to influence the relapse rate of the patients. Conclusions: Loss of CD30 expression occurs frequently in metastatic embryo nal carcinomas after chemotherapy. This finding has implications in the use of CD30 in the diagnosis of metastatic non-seminomatous germ cell tumours and suggests that chemotherapy may alter the immunophenotype of embryonal c arcinoma while retaining its characteristic histological appearances.