Imaging 
• Ultrasound is extremely accurate, and any solid mass found on ultrasound should be considered cancerous until
  proven otherwise.
• Chest x-rays to evaluate lung metastases. Many oncologists advise obtaining a baseline CT of the chest, even
  with a normal chest x-ray, to aid in follow-up.
• CT scans of the abdomen and pelvis are part of the staging procedure to evaluate the abdominal
  (retroperitoneal) and pelvic lymph nodes . Some physicians now use MRI instead of CT scans.
• Lymphangiography may help in about 10 percent of cases, but it is no longer routinely used because CT scans
  are more accurate. Sometimes it is still used to plan radiation therapy ports.
• X-ray tomograms of the chest have been largely replaced by the more accurate chest CT scan.
• Radionuclide bone and brain CT scans have to be done only when there are symptoms, although some doctors
  routinely order these scans for men with pure choriocarcinoma .

Biopsy 
• The removal of the testicle (orchiectomy) through an incision in the groin—never a scrotal incision or an
  aspiration biopsy—is required for diagnosis. Even when metastatic disease is found, the testis where the
  cancer started still has to be removed because the primary tumor does not always respond fully to
  chemotherapy .