Testicular germ cell tumours (TGCT) are malignancies that derive from premeiotic germ cells of the testis. TGCT are the most frequent malignancy in Caucasian Western men in the age group 25 to 35 years. During the last forty years, an increasing percentage of patients are cured (Sonneveld et al. 2001). Today, patients in the Nordic countries have a five-year survival of 82% to 90% (Engeland et al. 1995). The outcome became better because of improvements in all aspects in the management, such as staging, monitoring, and treatment (Anderson et al. 1981, Jones et al. 1981, Peckham, 1981, Rorth et al. 1987, Horwich, 1991, Oosterhuis et al. 1991, Jones et al. 1994, Rajpert- De Meyts et al. 1998, Harnden et al. 2001). Part of the progress in treatment is due to TGCT being diagnosed with shorter delays by patients and doctors than previously so that the tumours are diagnosed in a less advanced stage (Sonneveld et al. 1999)