onset most commonly occurs in males 20 to 34 years old, rarely before 15 years old
most are now highly treatable and usually curable even if spread has occurred
more than 95% of testicular cancers are germ cell tumors (GCTs), for example:
most of the remaining 5% are sex cord–gonadal stromal tumours derived from Leydig cells or Sertoli cells eg:
Leydig cell tumour
Sertoli cell tumour 2%
granulosa cell tumours
thecoma
fibroma
stromal tumours
in addition, lymphoma accounts for 8% of scrotal tumours while leukaemia causes 3%