Cancers of the testicles are usually found in young adults however it can occur at any age. It is a highly treatable and usually curable type of cancer. Testicular cancer accounts for less than 1% of all malignancies in males. They are sometimes associated with an undescended testicle. More than 90% of cancers of the testicle develop in special cells known as germ cells. These are the cells that make sperm. There are 2 main types of germ cell tumors (GCTs) in men: the seminomatous types and the non-seminomatous types.
Seminomas tend to grow and spread more slowly than non-seminomas. The 2 main subtypes of these tumors are classical (or typical) seminomas and spermatocytic seminomas. Doctors can tell them apart by how they look under the microscope.
Classical seminoma: More than 95% of seminomas are classical. These usually occur in men between 25 and 45.
Spermatocytic seminoma: This rare type of seminoma tends to occur in older men. The average age of men diagnosed with spermatocytic seminoma is about 65. Spermatocytic tumors tend to grow more slowly and are less likely to spread to other parts of the body than classical seminomas.
Some seminomas can increase blood levels of a protein called human chorionic gonadotropin (HCG). HCG can be detected by a simple blood test and is considered a tumor marker for certain types of testicular cancer. It can be used for diagnosis and to check how the patient is responding to treatment.
These types of germ cell tumors usually occur in men between their late teens and early 30s. There are 4 main types of non-seminoma tumors:
- Embryonal carcinoma
- Yolk sac carcinoma
Most tumors are a mix of 2 or more different types (sometimes with a seminoma component as well), but this does not change treatment. All non-seminoma cancers are treated the same way.