Lung cancer occurred in the bronchial epithelium also known as lung cancer. Lung cancer generally refers to the Ministry of cancer lung parenchyma, usually does not include other areas such as the origin of mesoderm pleural tumors (mesothelioma), or other malignant tumors such as carcinoid tumors (carcinoid), malignant lymphoma (malignant lymphoma), or transferred from other the source of tumors. So we said the following lung cancer, is from the bronchial (bronchial) or bronchioles (bronchiolar) epithelial cells (epithelial cell) malignant tumor, accounting for 90-95% of malignant lung parenchyma.
Pathology and classification of lung cancer (a) Classification by anatomic site
1. Central lung segment or segmental bronchi and above also include the total leaf, said the central bronchial lung cancer, 3 / 4 squamous cell carcinoma and small cell undifferentiated carcinoma were more common.
2. Peripheral segmental bronchus of lung cancer following cancer called peripheral lung cancer, accounting for about 1 / 4, adenocarcinoma common.
Lung pathology and classification (b) histologic classification of connected
1. Squamous cell carcinoma (squamous cell carcinoma) the most common, 40% _ 50%, common old men. A history of smoking, slow growth of cancer cells, transfer late on chemotherapy-sensitive, can be divided into well differentiated, moderately differentiated and poorly differentiated squamous cell carcinoma. Usually after the first lymph node metastasis, hematogenous metastasis occurs late.
2. Small cell undifferentiated carcinoma (small cell carcinoma) the highest degree of malignancy of lung cancer, accounting for about 10% – 15%, age 40 _ more than 50 years of age. Most of the central type lung cancer, oat cell is one of the subtypes, the cells and small lymphocytes similar shaped like oat grains. Small cell undifferentiated carcinoma rapid growth, early lymphatic and hematogenous metastasis occurs, is far more sensitive to radiotherapy and chemotherapy, but in all types of the worst prognosis.
3. Large cell undifferentiated carcinoma (large cell) are relatively rare, is a malignant epithelial tumors, is poorly differentiated squamous cell carcinoma, large cell nuclei irregularly. Already spread tendency to poor prognosis.
4. Adenocarcinoma of small age, women more common, more in the smaller bronchial epithelial origin, mostly peripheral lung cancer. Early general no obvious clinical symptoms, the general growth slow, but sometimes blood metastasis occurs early stage can lead to chest dirty effusion, and smoking has little to do.
5. Mixed 129 lung cancer accounted for 60% of gross _, as a squamous cell carcinoma and adenocarcinoma with two components of the cancer, the biological behavior of adenocarcinoma similar.
6. Carcinoid tumor is an endocrine system cancer, often occurring in large bronchial bi, showing papillary or polypoid prominence to the cavity, a number of central type. For multiple tumors, is a low grade malignant, the tumor is small, less shifted outwards.
7. Bronchial glands bronchial glands from the tumor, occurred in the trachea or larger bronchi.