A patchy shadow in the right lower lung is not necessarily cancer, but more likely an inflammatory exudate in the lung, such as pneumonia. Because of malignant tumors such as lung cancer, the imaging presentation is usually dominated by solid shadows, but sometimes due to obstruction of the bronchi by the lung cancer mass, resulting in obstructive pneumonia, inflammatory exudation may appear around the solid shadows, that is, patchy shadows, and at this time, a CT can reveal that part of the patchy shadows in a lung are solid. If a chest X-ray or CT examination reveals only a patchy shadow without a solid shadow, it is more likely to be an inflammatory exudate in the lung, such as pneumonia, alveolitis, or fibrotic lung lesion.