Biopsy
A small sample of tissue is taken from the targeted area in the testicle and examined under a microscope by a pathologist to determine whether the lump is malignant (cancerous) or benign (non-cancerous).

In most cases the only way to perform a biopsy safely is to remove the whole testicle - to perform an orchidectomy. This is because the risk of the cancer spreading if a conventional biopsy is taken is high. The specialist will only remove the testicle for a biopsy if it seems very likely the lump is cancerous. If a patient has two testicles and has one removed he can still produce sperm from the other one and procreate.

Blood tests
The aim here is to measure levels of tumor markers. Tumor markers are substances which exist in higher-than-normal levels when cancer is present. If levels of alpha-fetoprotein (AFP), human chorionic gonadotrophin (HCG), and lactate dehydrogenase (LDH) are higher than normal it may suggest there is a testicular tumor, even if a physical exam or imaging tests did not detect it.

Ultrasound
This is a test that uses high-frequency sound waves that bounce off internal organs and tissues. Their echoes are processed and a picture is viewed on a monitor. An ultrasound of the scrotum can reveal the presence and also the size of a tumor. The doctor may also be able to determine the nature of any lump, whether they are solid or filled with fluid, inside or outside the testicle. This information helps the health care provider decide whether or not the lump is cancerous.