Secondary lung cancer. Frontal X-ray of the lungs of a 72-year-old man with metastatic (secondary) lung cancer that has spread from a primary skin cancer (malignant melanoma). The secondary cancers are shown by the presence of numerous diffuse patches in the lungs. Once a cancer has spread, the prognosis is poor. The patient has been fitted with a pacemaker (centre right), and is undergoing chemotherapy (implanted catheter at top left).