The different types of testicular cancer are classified by the type of cells the cancer begins in.
The most common type of testicular cancer is "germ cell testicular cancer", which accounts for around 95% of all cases. Germ cells are a type of cell that the body uses to create sperm.
There are two main subtypes of germ cell testicular cancer. They are:
seminomas – which have become more common in the past 20 years and now account for 50 to 55% of testicular cancers
non-seminomas – which account for most of the rest and include teratomas, embryonal carcinomas, choriocarcinomas and yolk sac tumours
Both types tend to respond well to chemotherapy.
For more information see link below.
http://www.cancerresearchuk.org/about-cancer/testicular-cancer/symptoms