Most common malignancy in young men, 1% all cancers in men
Increased frequency in: infertile patients, whites, undescended testis, history of cryptorchidism
95% germ cell<unk> s: half seminomas, half mixed types (teratomas, choriocarcinomas, yolk sac<unk> s)
5% sex cord stromal<unk> s
Testicular tumor
Scrotal cellulitis
Spermatocele
Epididymitis
Hematocele
Fournier gangrene
Hydrocele 
Hydrocele