Most lumps in the scrotum aren't cancer. However, if you're worried, see your doctor. Your doctor will ask about your symptoms and examine you. The doctor will also ask you about your medical history. You may be referred to a specialist. An ultrasound scan can help diagnose cancer. You will also have blood tests to assess the levels of 'tumour markers'(proteins produced by a tumour).The only way to confirm testicular cancer is with a biopsy. In testicular cancer, the affected testicle will be removed completely. If only a small biopsy is done in the usual way, the risk of cancer spreading is high(hence its not done).You may be offered other tests to see if the cancer has spread.
Attribution: BUPA