肺癌是常见的恶性肿瘤,发病率和死亡率很高。有的国家肺癌发病率已占肿瘤第一位,我国已居第二位,且有持续增高的趋势。近年在早期诊断、治疗方面取得了很大进展。一般认为,由 X 线发现者多为周围型,由细胞学检查发现者多为中心型 Lung cancer is a common malignancy with high morbidity and mortality. In some countries, the incidence of lung cancer accounts for the first place in cancers, and China ranks second, and it continues to increase. In recent years, great progress has been made in early diagnosis and treatment. It is generally believed that most of the X-ray findings are peripheral, and those found by cytology are mostly centered.