It is the most common of all types of lung cancer, accounting for about 50% of lung cancers, and is mostly found in men over 50 years of age. Most of them originate from the larger bronchial tubes and are often centralized lung cancers. Although the degree of differentiation of squamous carcinoma varies, it usually grows slowly, has a longer course, and is more sensitive to radiation and chemotherapy. It is easy to metastasize via lymph first, and blood line metastasis occurs later.

Small cell carcinoma

Small cell carcinoma includes oat cell type, intermediate cell type and compound oat cell type. It is the most malignant type of lung cancer, accounting for 10%-15% of primary lung cancer. Patients are young, mostly in their 40s and 50s, and have a history of smoking. It mostly occurs in the large bronchial tubes near the hilum, tends to grow in the subungual layer, often invades the parenchyma outside the tubes, and is easy to merge with hilar and mediastinal lymph nodes to form clusters. The cancer cells grow fast, have strong invasive power and early distant metastasis.

Large cell carcinoma

Large cell carcinoma includes giant cell carcinoma and clear cell carcinoma. It can occur in the bronchioles near the hilum or at the edge of the lungs. The cells are large, but with different sizes, often polygonal or irregular, arranged in solid nests, with large hemorrhagic necrosis; the nuclei of the cancer cells are large, nucleoli are obvious, nuclear schizophrenia is common, cytoplasm is abundant, and they can be divided into giant cell-type and clear cell-type. The metastasis of large cell carcinoma is later than that of small cell undifferentiated carcinoma, and the chance of surgical resection is larger.