There are many types of lung cancer. More than 96% of lung cancer patients start from the bronchus and can be divided into two types, central type and peripheral type, depending on the location of onset. One type of lung cancer is central lung cancer: it develops in the central part of the lung. The types of lung cancer are divided differently according to other classifications. What are the types of lung cancer? Small cell lung cancer, also called oat cell carcinoma, accounts for about 20% of lung cancer. This type of lung cancer grows rapidly and can easily metastasize to other parts of the body. The cause of small cell lung cancer is inextricably linked to smoking. The treatment of small cell lung cancer is mainly chemotherapy, together with radiation therapy. Bronchial carcinoid tumor mostly appears under the mucosa of bronchus, and when it bursts into the lumen of bronchus, it forms a polyp-like mass with smooth surface and rich blood vessels, which is easy to bleed. In some cases, the tumor grows both inside and outside the bronchial wall, forming a mass in the bronchial cavity and lung, which is similar to the shape of a dumbbell, and this is also one of the types of lung cancer. 3.Peripheral type lung cancer usually occurs in the periphery of the lung, so it usually does not produce symptoms of cough and hemoptysis, some patients may have hidden pain, dull pain, or intermittent pain in the chest, but when the tumor increases. In order to prevent misdiagnosis, it is best to perform surgery in time for patients who are over forty years old and suddenly find round shadows in the lungs that cannot be diagnosed as tuberculosis. 4.Non-small cell lung cancer About 80% of lung cancer patients get non-small cell lung cancer. This type of cancer grows and spreads slowly compared to small cell lung cancer. Non-small cell lung cancer includes three types: squamous carcinoma, adenocarcinoma and large cell lung cancer, which have different cell types. The cause of most non-small cell lung cancers is related to smoking, but the cause of a few cases of adenocarcinoma and many cases of large cell lung cancer is unknown. Treatment for early-stage non-small cell lung cancer is primarily surgery with chemotherapy and radiation. Patients with advanced stages mainly receive a combination of chemotherapy and radiotherapy. 5.Bronchial cystic adenoid carcinoma, also known as cylindrical adenoma, is one of the rare types of lung cancer. It occurs in the mucosal secretory glands of the adenohypophysis or bronchus. Most of them occur in the lower trachea or proximal raw bronchi. It is highly malignant and often erodes the tracheal or bronchial wall and surrounding tissues, causing obstruction of the bronchial lumen and lymph nodes or distant metastases. The tumor cells are arranged like a sieve, interwoven into a column, with gaps in the middle, and contain eosinophilic material. Mucinous epithelioid carcinoma is a rare type of lung cancer. It occurs in the bronchial mucosal secretory glands in the lung lobes and looks similar to polyps with intact surface mucosa and mucus secretion at the same time. Microscopic examination of the tumor consists of a mixture of squamous epithelial cells and mucus-secreting columnar cells. It is relatively low in severity, but has an erosive effect on nearby tissues.