Pathogenesis of testicular germ cell tumours.

Testicular germ cell tumours are subdivided clinically into two major groups: seminomas and non-seminomatous germ cell tumours (NSGCT). The relationship of seminomas to NSGCT remains controversial. The pathogenesis of NSGCT has been studied experimentally in mice, but there are no adequate experimental models of seminomas in laboratory rodents. Experiments with tumour cell lines derived from animal tumours have generated useful data for the better understanding of the biology of stem cells, such as embryonal carcinoma and yolk sac tumour. The final answer to questions pertaining to the histogenesis and classification of human germ cell tumours will however be obtained only after appropriate tumour cell lines of human origin are cloned.