Lesion on fourth lumbar, cyst on kidneys

Patient: I was in wreck about a month ago, and I started having lower back pain, neck, and hip pain. When I went to the doctor they took an MRI and found a lesion on my fourth lumbar. Can you please tell me what this is and could it be cancer? They also found fluid-filled cyst on my kidneys. What could this mean? I go back for a urine test Friday, but I am really worried about this and need some kind of explanation. Maybe you could help me please.