Testicular germ cell tumours. Current problems of histogenesis and classification.

Testicular germ cell tumours, owing to their variety in biological behaviour and morphological appearance, claim a place of their own in clinical oncology and tumour research. Much of the histogenesis has remained unexplained, as reflected by the different systems of pathological classification. This report sums up, on basis of the literature, the current pathologic views on the question of testicular tumour genesis. Data obtained from immune histochemical examinations, animal experiments, ultrastructure studies, together with clinical observations, suggest that differentiation of the carcinomatous stem cells are apt to produce forms, transitional between seminomatous and non-seminomatous types of tumour. The possibility to set up a uniform, clinically appropriate nomenclature depends on the progress in histogenetic knowledge.