Testicular germ cell tumours of childhood in Denmark, 1943-1989: incidence and evaluation of histology using immunohistochemical techniques.

In the Danish Cancer Registry, 72 testicular tumours in boys younger than 15 years of age were recorded during the period 1943-1989 and material from 34 of these was retrieved from Danish departments of pathology. The histological types were evaluated and the role of immunohistochemical staining was analysed. The survival of the patients was correlated with the histological diagnoses, and changes in the incidence of testicular cancers in childhood were analysed. Twenty-nine of the 34 patients had germ cell tumours, which fell into two groups (infantile and pubertal) with distinct differences. The tumours of infancy usually presented before the age of 3 years and were either pure yolk sac tumours or teratomas. The tumours of puberty showed no morphological or immunohistochemical differences from adult germ cell tumours. In the infantile group, immunohistochemical staining confirmed the morphological evaluation but was not necessary for diagnosis. Patients in the infantile group seemed to have a better prognosis than adult patients, only one patient dying from his disease, whereas the pubertal patients seemed to have a prognosis similar to that of adult patients. The incidence of infantile testicular cancer in Denmark appears to have increased at almost the same rate as that observed in adult men, but due to the small numbers in infancy, this cannot be statistically substantiated. We conclude that the testicular germ cell tumours of infancy and puberty may arise from different precursor cells, but both groups seem to arise prenatally.