Serial xenotransplantation of a human embryonal carcinoma in experimental urology.

The rare incidence of testicular germ cell tumours makes it necessary for clinicians to look for a valid experimental model to investigate basic tumour properties and different therapeutic modalities preclinically in order to improve clinical cure rates. A human embryonal carcinoma with hCG-production was successfully established in nude mice for more than 40 passages. We were able to show striking maintenance of histological and ultrastructural features, tumour markers (Beta-hCG) and DNA indices of the original tumour during subsequent xenograft passages as well as stability of tumour growth. Dedifferentiation of the tumour with changing growth fractions or loss of hCG production was not evident.