The first step in diagnosing parathyroid cancer is a physical exam in which your doctor will feel your parathyroid glands through your neck. Blood tests can confirm a suspicion of parathyroid cancer. Your doctor will measure the levels of calcium and parathyroid hormone in your blood. If they are extremely above normal levels, you may have parathyroid cancer. Scans and ultrasounds can determine where in your parathyroid glands cancer is located.