Definition
Lung cancer is a malignant tumour that affects the bronchi (99%) or alveoli (1%). The majority of cases are linked to bronchial involvement, which can lead to obstruction and local spread in the lung tissue.
Classification
- Primary cancer: Grows into the bronchial lumen
- Typically begins in the bronchial epithelium and can obstruct airflow.
- Metastatic cancer: Infiltrates the bronchial wall and interstitial tissue
- Metastases from other cancers can spread to the lungs, affecting both the parenchyma and pleura.
Based on localisation:
- Central: Affects the main bronchi or their branches
- Usually presents with obstruction symptoms, like coughing and SOB.
- Peripheral: Affects small bronchi, located near the chest wall
- More commonly found in the outer regions of the lungs and can grow silently in early stages.
- Apical cancer (Pancoast-Tobias): Located at the lung apex, often involving the upper lobes, and can extend to the brachial plexus.
- Pancoast tumors cause shoulder pain, nerve damage, and sometimes Horner’s syndrome (ptosis, miosis, enophthalmus).