Pathological characteristics of lung cancer

There are two ways to classify non-small cell lung cancer based on the location and growth pattern of the tumor.

According to the location of the tumor, it is divided into the following three types: ① Central type: The tumor occurs in the main bronchi, lobar bronchi and segmental bronchi. ② Peripheral type: The tumor occurs in the small bronchi and bronchioles below the segmental bronchi. ③ Diffuse type: The tumor occurs in the bronchioles and alveoli and spreads diffusely in the lungs.

According to the tumor growth pattern, it is divided into the following 6 types: ① intravascular type, ② wall-infiltrating type, ③ massive type, ④ spherical type, ⑤ nodular type, and ⑥ diffuse infiltrating type.

In 1997, the World Health Organization (WHO) classified NSCLC histological types into the following 7 types.

1. Squamous cell carcinoma, including papillary, clear cell, small cell, and basaloid carcinoma.

2. Adenocarcinoma, including acinar, papillary, bronchioloalveolar, solid and mucinous, and mixed types.

3. Large cell carcinoma, including large cell neuroendocrine type, basaloid, lymphoepithelial, clear cell, and large cell with rhabdoid phenotype.

4. Adenosquamous carcinoma.

5. Pleomorphic carcinoma with sarcomatous components, including carcinoma with spindle cells and/or giant cell carcinoma, carcinosarcoma, and pulmonary blastoma.

6. Carcinoid, including typical carcinoid and atypical carcinoid.

7. Salivary gland carcinoma, salivary gland epidermoid carcinoma, adenoid cystic carcinoma.